[HN Gopher] Cursor's latest "browser experiment" implied success...
___________________________________________________________________
Cursor's latest "browser experiment" implied success without
evidence
Related: _Scaling long-running autonomous coding_ -
https://news.ycombinator.com/item?id=46624541 - Jan 2026 (174
comments)
Author : embedding-shape
Score : 688 points
Date : 2026-01-16 14:37 UTC (1 days ago)
(HTM) web link (embedding-shapes.github.io)
(TXT) w3m dump (embedding-shapes.github.io)
| embedding-shape wrote:
| I'm eager to find out if this was actually successfully compiled
| at one point (otherwise how did they get the screenshots?), so
| I'm running `cargo check` for each of the last 100 commits to see
| if anything works. Will update here with the results once it's
| ready.
|
| Edit: As mentioned, I ran `cargo check` on all the last 100
| commits, and seems every single of them failed in some way:
| https://gist.github.com/embedding-shapes/f5d096dd10be44ff82b...
| techpression wrote:
| I wouldn't be surprised if any form of screen shot is fake (as
| in not made the way it claims), in my experience Occam's razor
| tends to lead that way when extraordinary claims are made
| regarding LLM's.
| leerob wrote:
| Should compile now:
| https://news.ycombinator.com/item?id=46650998
| embedding-shape wrote:
| > Yeah, seems latest commit does let `cargo check`
| successfully run. I'm gonna write an update blog post once
| they've made their statement, because I'm guessing they're
| about to say something.
|
| > Sometime fishy is happening in their `git log`, it doesn't
| seem like it was the agents who "autonomously" actually made
| things compile in the end. Notice the git username and email
| addresses switching around, even a commit made inside a EC2
| instance managed to get in there:
| https://gist.github.com/embedding-
| shapes/d09225180ea3236f180...
|
| Gonna need to look closer into it when I have time, but seems
| they manually patched it up in the end, so the original claim
| still doesn't stand :/
| saghm wrote:
| > otherwise how did they get the screenshots
|
| Their AI is probably better at producing images than writing
| code
| josefritzishere wrote:
| Key phrase "They never actually claim this browser is working and
| functional " This is what most AI "successes" turn out to be when
| you apply even a modicum of scrutiny.
| embedding-shape wrote:
| In my personal experience, Codex and Claude Code are
| definitively capable tools when used in certain ways.
|
| What Cursor did with their blogpost seems intentionally and
| outright misleading, since I'm not able to even run the thing.
| With Codex/Claude Codex it's relatively easy to download it and
| run it to try for yourself.
| netdevphoenix wrote:
| "definitively capable tools when used in certain ways". This
| sounds like "if it doesn't work for you is because you don't
| use in the right way" imo.
|
| Reminds me of SAAP/Salesforce.
| embedding-shape wrote:
| Yes, many tools work like that, especially professional
| tools.
|
| You think you can just fire up Ableton, Cubase or whatever
| and make as great music as a artist who done that for a
| long time? No, it requires practice and understanding.
| Every tool works like this, some different difficulties,
| some different skill levels, but all of them have it in
| some way.
| immibis wrote:
| Not even the Ableton marketing team is telling me I can
| just fire up Ableton and make great music and if I can't
| do that I must be a brainwashed doomer.
| embedding-shape wrote:
| The argument isn't what OpenAI/Anthropic are selling
| their users, what I said was:
|
| > are definitively capable tools when used in certain
| ways
|
| Which I received pushback on. My reply is to that
| pushback, defending what I said, not what others told
| you.
|
| Edit: Besides the point, but Ableton (and others)
| constantly tell people how to learn how to use the tool,
| so they use it the right way. There is a whole industry
| of people (teachers) who specialize in specific
| software/hardware and teaching others "how to hold the
| tool correctly".
| Xorakios wrote:
| or the iPhone...
| Capricorn2481 wrote:
| > Besides the point, but Ableton (and others) constantly
| tell people how to learn how to use the tool, so they use
| it the right way
|
| It's just an odd comparison to begin with. You said
|
| > You think you can just fire up Ableton, Cubase or
| whatever and make as great music as a artist who done
| that for a long time
|
| I don't think you have to be good at Ableton at all to
| make good music. I don't think you can even argue it
| would benefit your music to learn Ableton. There's a crap
| ton of people who are wizards with their DAW making
| mediocre music. A DAW can be fun to learn, and that can
| help me keep my flow state. But it's not literally going
| to make better music, and the fundamentals of production
| don't change at all from DAW to DAW.
|
| That's a totally separate thing from LLMs. We are
| constantly told that if we learn the magic way to use
| LLMs, we can spit out functioning code a lot faster. But
| in reality, people are just generating code faster than
| they can verify it.
| embedding-shape wrote:
| > That's a totally separate thing from LLMs. We are
| constantly told that if we learn the magic way to use
| LLMs, we can spit out functioning code a lot faster. But
| in reality, people are just generating code faster than
| they can verify it.
|
| I don't see it as it is. LLMs are not magically gonna
| make you be able to produce high-quality software, just
| like Ableton isn't gonna magically gonna make you be able
| to produce high-quality music. But if you learn the tool,
| it gets a lot easier to use effectively. And the better
| you are at "producing high quality music/code", probably
| the more use you can make of Ableton/LLMs, compared to
| someone who aren't good at those things already.
|
| Again, what you're being told by other people, I don't
| know, and frankly don't really care. OpenAI sold Codex to
| me as a tool that can help me, a programmer, do
| programming, and that's exactly what that tool gives me.
|
| Cursor in their article tried to sell their tool as
| something that can "Hundreds of agents can work together
| on a single codebase for weeks, making real progress on
| ambitious projects" which I claim in TFA, doesn't seem to
| be true.
| deathanatos wrote:
| This is the company making the tool that is holding the
| tool, in this case, claiming that "[they] built a
| browser" when, if TFA's assertions are correct, they did
| not "build a browser" by any reasonable interpretation of
| those words.
|
| (I grant that _you 're_ speaking from _your_ experience,
| about different tools, two replies up, but this claims is
| just paper-rock-scissorable through these various AI
| tools. "Oh, this tool's authors are just hype, but
| _this_ tool works totes-mc-oates... ". Fool me once, and
| all.)
| embedding-shape wrote:
| Yes, and apparently is a horrible way, because they've
| obviously failed to produce a functioning browser. But
| since I'm the author of TFA, I guess I'm kind of biased
| in this discussion.
|
| Codex was sold to me as a tool that can help me do
| program. I tried it, evaluated it, found it helpful,
| continued using it. Based on my experience, it
| definitively helps with some tasks. Apparently also, it
| does not work for others, for some not at all. I know the
| tool works for me, and I take the claim that it doesn't
| for others, what am I left to believe in? That the tool
| doesn't actually work, even though my own experience and
| usage of it says otherwise?
|
| Codex is still an "AI success", regardless if it could
| build an entire browser by itself, from scratch, or
| whatever. It helps as it is today, I wouldn't need it to
| get better to continue using it.
|
| But even with this perspective, which I'd say is
| "nuanced" (others would claim "AI zealot" probably), I'm
| trying to see if what Cursor claims is actually true,
| that they managed to build a browser in that way. When it
| doesn't seem true, I call it out. I still disagree with
| "This is what most AI "successes" turn out to be when you
| apply even a modicum of scrutiny", and I'm claiming what
| Cursor is doing here is different.
| airstrike wrote:
| FWIW IMHO Windsurf is better than Cursor. Claude Code is
| better than both for many tasks, but not all.
| epolanski wrote:
| > if it doesn't work for you is because you don't use in
| the right way
|
| That's an almost universal truth that you need to learn how
| to use any non trivial tool.
| Kiro wrote:
| > "definitively capable tools when used in certain ways".
| This sounds like "if it doesn't work for you is because you
| don't use in the right way" imo.
|
| Yes, because that's what it is. If you seriously can't get
| Gemini 3 or Opus 4.5 to work you're either using it wrong
| or coding on something extremely esoteric.
| falloutx wrote:
| > Codex and Claude Code are definitively capable tools when
| used in certain ways.
|
| They definitely can make some things better and you can do
| somethings faster, but all the efficiency is gonna get sucked
| up by companies trying to drop more slop.
| hexbin010 wrote:
| No you see you just need to _prompt_ it to implement functional
| and working code. You 're just inexperienced and holding it
| wrong
| falloutx wrote:
| $200/month tool (real cost could be $1000/month), but you
| have to babysit it.
| hexbin010 wrote:
| Yes that's _completely_ expected. Just like _any other_
| tool or service.
|
| It's just like a chisel. Well the chisel company didn't
| promise to let you become a master craftsman overnight but
| anyway it's just like a chisel in that you have to _learn_
| how to use it. And people expect a chisel to actually
| chisel through wood out the box but anyway it 's _exactly_
| like a chisel.
| ares623 wrote:
| Last I checked the chisel industry promised way less and
| didn't hold the entire planet's economy hostage
| falloutx wrote:
| chisel works exactly as advertised but Claude thinks I
| can use it to cure cancer by Tuesday.
| 7777777phil wrote:
| I wonder who they actually tried to impress with that? People who
| understand and appreciate the difficulty of building a browser
| from scratch would surely be interested to understand what you
| (or your Agent) did to a degree that they would understand if you
| didn't.
| koolala wrote:
| It worked to impress people on Twitter...
| thewhitetulip wrote:
| You'll see countless posts on LinkedIn about how great LLM is.
| Nobody goes in depth these days - just superficial posts
| Snuggly73 wrote:
| Not sure - if it works, then who needs Cursor (and all other
| IDEs). You just ask for a browser and it comes out of the thin
| air.
| fernandotakai wrote:
| >I wonder who they actually tried to impress with that?
|
| investors?
| paulus_magnus2 wrote:
| The blog[0] is worded rather conservatively but on Twitter [2]
| the claim is pretty obvious and the hype effect is achieved [2]
|
| CEO stated "We built a browser with GPT-5.2 in Cursor"
|
| instead of
|
| "by dividing agents into planners and workers we managed to get
| them busy for weeks creating thousands of commits to the main
| branch, resolving merge conflicts along the way. The repo is 1M+
| lines of code but the code does not work (yet)"
|
| [0] https://cursor.com/blog/scaling-agents
|
| [1] https://x.com/kimmonismus/status/2011776630440558799
|
| [2] https://x.com/mntruell/status/2011562190286045552
|
| [3]https://www.reddit.com/r/singularity/comments/1qd541a/ceo_of..
| .
| embedding-shape wrote:
| So clearly someone, at some point, managed to run this, surely?
| That's where the screenshots come from? I just don't understand
| how, given the code is riddled with errors.
| deeth_starr_v wrote:
| Maybe they just asked an AI to create an image of a rendered
| webpage?
| nicoburns wrote:
| Somebody managed to get it to compile
| https://x.com/CanadaHonk/status/2011612084719796272
|
| But apparently "some pages take a literal minute to load"
| embedding-shape wrote:
| > to be clear those 2 hours were fixing compile errors and
| bugs, not compile time
|
| Seems like "I had to do the last mile myself", not
| "autonomous coding" which was Cursor's claim here.
| deng wrote:
| Even then, "resolving merge conflicts along the way" doesn't
| mean anything, as there are two trivial merge strategies that
| are always guaranteed to work ('ours' and 'theirs').
| fzzzy wrote:
| that's not guaranteed to work. Other parts of the CodeBase
| that didn't conflict could depend on the discarded code.
| formerly_proven wrote:
| Well they did mention the code doesn't work.
| nyeah wrote:
| Where did Cursor say that?
| logicallee wrote:
| It's implied by the fact that early in the post they say:
|
| >"To test this system, we pointed it at an ambitious
| goal: building a web browser from scratch."
|
| and then near the end, they say:
|
| >"Hundreds of agents can work together on a single
| codebase for weeks, making real progress on ambitious
| projects."
|
| This means they only make progress toward it, but do not
| "build a web browser from scratch".
|
| If you're curious, the State of Utopia (will be available
| at https://stateofutopia.com ) did build a web browser
| from scratch, though it used several packages for the
| networking portion of it.
|
| See my other comments and posts for links.
| madeofpalk wrote:
| The point is that the merge conflict was resolved,
| regardless of whether there was a working product at the
| end. Which there apparently isn't.
| paulus_magnus2 wrote:
| Haha. True, CI success was not part of PR accept criteria at
| any point.
|
| If you view the PRs, they bundle multiple fixes together, at
| least according to the commit messages. The next hurdle will
| be to guardrail agents so that they only implement one task
| and don't cheat by modifying the CI piepeline
| formerly_proven wrote:
| If I had a nickel for every time I've seen a human dev
| disable/xfail/remove a failing test "because it's wrong"
| and then proceeding to break production I would have
| several nickels, which is not much, but does suggest that
| deleting failing tests, like many behaviors, is not LLM-
| specific.
| vizzier wrote:
| > but does suggest that deleting failing tests, like many
| behaviors, is not LLM-specific.
|
| True, but it is shocking how often claude suggests just
| disabling or removing tests.
| ciaranmca wrote:
| 100%, trying a bit of an experiment like this(similar in
| that I mostly just care about playing around with
| different agents, techniques etc.) it has built out
| literally hundreds of tests. Dozens of which were almost
| pointless as it decided to mock apis. When the number of
| failed tests exceeded 40 it just started disabling tests.
| icedchai wrote:
| To be fair, many human developers are fond of pointless
| tests that mock everything to the extent that no real
| code is actually exercised. At least the tests are fast
| though.
| falkensmaize wrote:
| Citing the absolute worst practices from terrible
| developers as a way to exonerate or legitimize LLM code
| production issues is something we need to stop doing in
| my opinion. I would not excuse or expect a day one junior
| on my team that wrote pointless tests or worse yet
| removed tests to get the CI to pass.
|
| If LLMs do this it should be seen as an issue and should
| not be overlooked with "people do it too...".
| Professional developers do not do this. If we're going to
| use Ai for creating production code we need to be honest
| about its deficiencies.
| icedchai wrote:
| I agree, but if LLMs are trained on common practices,
| best or worst, what do you expect?
|
| Testing, specifically, is heavily opinionated among
| professional developers.
| zephen wrote:
| > it is shocking how often claude suggests just disabling
| or removing tests.
|
| Arguably, Claude is simply successfully channeling what
| the developers who wrote the bulk of its training data
| would do. We've already seen how bad behavior injected
| into LLMs in one domain causes bad behavior in other
| domains, so I don't find this particularly shocking.
|
| The next frontier in LLMs has to be distinguishing good
| training data from bad training data. The companies have
| to do this, even if only in self defense against the new
| onslaught of AI-generated slop, and against deliberate
| LLM poisoning.
|
| If the models become better at critically distinguishing
| good from bad inputs, particularly if they can learn to
| treat bad inputs as examples of what not to do, I would
| expect one benefit of this is that the increased ability
| of the models to write working code will then greatly
| increase the willingness of the models to do so, rather
| than to simply disable failing tests.
| icedchai wrote:
| A coworker opened a PR full of AI slop. One of the first
| things I do is check if the tests pass. Of course, the
| didn't. I asked them to fix the tests, since there's no
| point in reviewing broken code.
|
| "Fix the tests." This was interpreted literally, and
| assert status == 200 got changed to assert status == 500
| in several locations. Some tests required more complex
| edits to make them "pass."
|
| Inquiries about the tests went unanswered. Eventually the
| 2000 lines of slop was closed without merging.
| saghm wrote:
| After a certain point the response to low effort vibe
| code has to be vibe reviews. Failing tests? Bad vibes,
| close without merging. Much more efficient than vibe
| coding too, since no AI is needed.
| ewoodrich wrote:
| The sneaky move that I hate most is when Claude (and does
| seem to mostly be a Claude-ism I haven't encountered on
| GPT Codex or GLM) is when dealing with an external data
| source (API, locally polling hardware, etc) as a
| "helpful" fallback on failures it returns fake data in
| the shape of the expected output so that the rest of the
| code "works".
|
| Latest example is when I recently vibe coded a little
| Python MQTT client for a UPS connected to a spare
| Raspberry Pi to use with Home Assistant, and with a just
| few turns back and forth I got this extremely cool
| bespoke tool and felt really fun.
|
| So I spent a while customizing how the data displayed on
| my Home Assistant dashboard and noticed every single data
| point was unchanging. It took a while to realize because
| the available data points wouldn't be expected to change
| a whole lot on a fully charged UPS but the voltage and
| current staying at the exact same value to a decimal
| place for three hours raised my suspicions.
|
| After reading the code I discovered it had just used one
| of the sample command line outputs from the UPS tool I
| gave it to write the CLI parsing logic. When an exception
| occurred in the parser function it instead returned the
| sample data so the MQTT portion of the script could still
| "work".
|
| Tbf Claude did eventually get it over the finish line
| once I clarified that yes, using real data from the
| actual UPS was in fact an important requirement for me in
| a real time UPS monitoring dashboard...
| teiferer wrote:
| Always check the code.
|
| It's similar to early versions of autonomous driving.
| You's not want to sit in the back seat with nobody at the
| wheel. That would get you killed guaranteed.
| DonHopkins wrote:
| And how is that not good for humanity in an evolutionary
| sense (as long as it doesn't kill or maim anyone else)?
|
| Tesla owner keeps using Autopilot from backseat--even
| after being arrested:
|
| https://mashable.com/article/tesla-autopilot-arrest-
| driving-...
| duskdozer wrote:
| Sounds to me like more evidence in favor of the idea that
| they're meant to play the golden retriever engineer
| reporting to you, the extremely intelligent manager.
| dullcrisp wrote:
| If I had a nickel for every time I've seen a human being
| pull down their pants and defecate in the middle of the
| street I'd have a couple nickels. That's not a lot but it
| suggests that this behavior is not LLM specific.
| mickdarling wrote:
| Had humans not been doing this already, I would have
| walked into Samsung with the demo application that was
| working an hour before my meeting, rather than the
| android app that could only show me the opening logo.
|
| There are a lot of really bad human developers out there,
| too.
| moregrist wrote:
| > Entrepreneur, CEO and founder of Tomorrowish a social
| media DVR
|
| So you flubbed managing a project and are now blaming
| your employees. Classy.
| DonHopkins wrote:
| Nice blog post, gp serial entrepreneur founder bro --
| what did your investors think of that?
|
| http://www.mickdarling.com/2019/07/26/busy-summer/
| An embedded page at landr-atlas.com says:
| Attention! MacOS Security Center has
| identified that your system is under threat.
| Please scan your MacOS as soon as possible to avoid more
| damage. Don't leave this page until you have
| undertaken all the suggested steps by authorised
| Antivirus. [OK]
| mickdarling wrote:
| Wasn't my project to manage. That was a consulting gig.
| And I fired the client right after this.
| teiferer wrote:
| Where I work, that's exceptionally rare to the point
| practically non-existing.
| Tade0 wrote:
| If anything, the LLMs had to learn that from somewhere,
| so they're just copying human behaviour.
| aspenmartin wrote:
| I'm definitely in the camp that this browser
| implementation is shit, but just a reminder: agent
| training does involve human coding data in early stages
| of training to bootstrap it but in its reinforcement
| learning phase it does not -- it learns closer to the way
| AlphaGo did, self play and verifiable rewards. This is
| why people are very bullish on agents, there is no limit
| technically to how well they can learn (unlike LLMs) and
| we _know_ we will reach superhuman skill, and the crucial
| crucial reason for this is: verifiable rewards. You have
| this for coding, you do not have this for e.g. creative
| tasks etc.
|
| So agents _will_ actually be able to build a {browser,
| library, etc} that won 't be an absolute slopfest, but
| the real crucial question is _when_. You need better and
| more efficient RL training, further scaling (Amodei
| thinks really scaling is the only thing you technically
| need here and we have about 3-4 orders of magnitude of
| headroom left before we hit insurmountable limits),
| bigger context windows (that models actually handle well)
| and possibly continual learning paradigms, but solutions
| to these problems are quite tangible now.
| PunchyHamster wrote:
| So, AI agent battle royale
| anonzzzies wrote:
| We use claude code a lot for updating systems to a newer
| minor/major version. We have our own 'base' framework for
| clients which is a, by now, very large codebase that does
| 'everything you can possibly need'; so not only auth, but
| payments, billing, support tickets, email workflows, email
| wysiwyg editing, landing page editor, blogging, cms, AI
| /agent workflows etc etc (across our client base, we collect
| features that are 'generic' enough and create those in the
| base). It has many updates for the product lead working on it
| (a senior using Claude code) but we cannot just update our
| clients (whose versions are sometimes extremely
| customised/diverging) at the same pace; some do not want
| updates outside security, some want them once a year etc. In
| this case AI has been really a productivity booster; our
| framework always was quite fast moving before AI too when we
| had 3.5 FTE (client teams are generally much larger,
| especially the first years) on it but then merging, that to
| mean; including the new features and improvements in the
| client version that are in the new framework version without
| breaking/removing changes on the client side, was a very
| painful process taking a lot of time and at at least 2 people
| for an extended period of time; one from the client team, one
| from the framework team. With CC it is much less painful: it
| will merge them (it is not allowed, by hooks, to touch the
| tests), it will run the client tests and the new framework
| tests and report the difference. That difference is evaluated
| usually by someone from the client team who will then merge
| and fix the tests (mostly manually) to reflect the new
| reality and test the system manually. Claude misses things
| (especially if functionalities are very similar but not
| exactly the same, it cannot really pick which to take so it
| does nothing usually) but the biggest bulk/work is done
| quickly and usually without causing issues.
| nyeah wrote:
| The link [0] implies that the browser worked. Can you help me
| understand what's "conservative" about that?
| DonHopkins wrote:
| > Can you help me understand what's "conservative" about
| that?
|
| It's the gaslighting.
| emp17344 wrote:
| This is why AI skeptics exist. We're now at the point where you
| can make entirely unsubstantiated claims about AI capability, and
| even many folks on HN will accept it with a complete lack of
| discernment. The hype is out of control.
| embedding-shape wrote:
| > folks on HN will accept it with a complete lack of
| discernment
|
| Well, I'm a heavy LLM user, I "believe" LLM helps me a lot for
| some tasks, but I'm also a developer with decades of
| experience, so I'm not gonna claim it'll help non-programmers
| to build software, or whatever. They're tools, not solutions in
| themselves.
|
| But even us "folks on HN" who generally keep up with where the
| ecosystem is going, have a limit I suppose. You need to
| substantiate what you're saying, and if you're saying you've
| managed to create a browser, better let others verify that
| somehow.
| emp17344 wrote:
| Take a look at this thread regarding the original claim:
| https://news.ycombinator.com/item?id=46624541
|
| The top comment is indeed baseless hype without a hint of
| skepticism.
| embedding-shape wrote:
| The second top comment is my own (skeptical) comment, with
| 20 points at this moment. Thanks to those 20 people, I felt
| compelled to write the blog-post in this submission, and
| try to ask a bit clearer "what is going on?", since
| apparently we're at least 20 people who is wondering about
| this.
|
| There is also clearly a lot of other skeptical people in
| that submission too. Also, simonw (from that top comment)
| told me themselves "it's not clear that what they built
| even runs": https://bsky.app/profile/simonwillison.net/post
| /3mckgw4mxoc2...
| blibble wrote:
| > The top comment is indeed baseless hype without a hint of
| skepticism.
|
| and he wonders why people call him a shill
|
| accepting everything some shit company tells you as gospel
| is not the default position of a "researcher"
|
| he better hope he's on the right side of history here, as
| otherwise he will have burnt his reputation
| emp17344 wrote:
| I certainly don't think Simon is a shill. He's obviously
| a highly talented person, who in my opinion just doesn't
| exercise appropriate discernment in some cases.
|
| Edit: Of course, this isn't a trait unique to Simon
| either. Everybody has blind spots, and it's reasonable to
| be excited when new tech is released. On an unrelated
| note, my intent is to push back against some of the
| people here who try to shut down skepticism. Obviously,
| this doesn't describe Simon, but I've seen others here
| who try to silence skeptical voices. This comes across as
| highly controlling and insecure.
| simonw wrote:
| See comment here:
| https://news.ycombinator.com/item?id=46646777#46650837
|
| I do not think you are reacting to what I said in good
| faith.
|
| > he better hope he's on the right side of history here,
| as otherwise he will have burnt his reputation
|
| That's something I've actually given quite a lot of
| thought to. My reputation and credibility matters a great
| deal to me. If it turns out this entire LLM thing was an
| over-hyped scam I'll take a very big hit to that
| reputation, and I'll deserve it.
|
| (If AI rises up and tries to kill or enslave us all I'll
| be too busy fighting back to care.)
| simonw wrote:
| As usual, I was careful with my words:
|
| > This project from Cursor is the second attempt I've seen
| at this now!
|
| I used the word "attempt" very deliberately, to avoid
| suggesting that either of these two projects had achieved
| the goal.
|
| I don't see how you can get to "baseless hype without a
| hint of skepticism" there unless you've already decided to
| take anything I say in bad faith.
| habinero wrote:
| C'mon. Your comment starts with you hyping your own
| prediction and crowing, "See, it's coming true!"
|
| "But I didn't say this exact word!" and then accusing the
| other person of bad faith is some textbook DARVO.
| simonw wrote:
| Right, because it IS _coming_ true (gotta be careful with
| that word choice - "coming true" and "has come true"
| mean different things.)
|
| There are already multiple attempts at building a from-
| scratch browser with LLM assistance. Unsurprisingly none
| of them have achieved full working browser status yet,
| several weeks after their attempts started.
| ben_w wrote:
| > but I'm also a developer with decades of experience, so I'm
| not gonna claim it'll help non-programmers to build software,
| or whatever. They're tools, not solutions in themselves.
|
| Also with decades experience, I'd say that it depends how big
| the non-programmer is dreaming:
|
| To agree with you: A well-meaning friend sent an entrepreneur
| my direction, whose idea was "Uber for aircraft". I tried to
| figure out exactly what they meant, ending the conversation
| when I realised all answers were rephrasing of that vague
| three words pitch, that they didn't really know what they
| wanted to _do_ in any specific enumerable sense.
|
| LLMs can't solve the problem when even the person asking
| doesn't know what they want.
|
| But on the other end the scale, I've been asked to give an
| estimate for an app which, in its entirety, would've been one
| day's work even with the QA and acceptance testing and going
| through the Apple App Store upload process. Like, I kept
| asking if there was any other hidden complexity, and nope,
| the entire pitch was what you'd give as a pre-interview code-
| challenge.
|
| An LLM would've spat out the solution to that in less time
| than I spent with the people who'd asked me to estimate it.
| geooff_ wrote:
| I think the original post was just headline bait. There is such a
| fast news cycle around AI that many people would take "Thousands
| of AI agents collaborate to make a web browser" at face value.
| embedding-shape wrote:
| At least I now have something to link to, when this inevitable
| gets mentioned in some off-hand HN comment, about how "now AI
| agents can build whole browsers from scratch".
| gusmally wrote:
| It's a great post, I will use it for the same. Thank you.
| buggy6257 wrote:
| Literally happened at work. Breathless thread of people
| saying how insane it was and then we got to link this and it
| immediately 180-ed and everyone was like "holy shit that's
| messed up"
| embedding-shape wrote:
| And I haven't even published part 2 yet!
| fernandotakai wrote:
| yup, same. slack thread with a lot of comments with people
| praising it.
|
| others were quite skeptical, specially the ones that
| actually perused the code.
| themafia wrote:
| A fast news cycle around projects that don't actually work.
| It's a real bummer that "fake news" became politically charged
| because it's a perfect description of this segment.
| nindalf wrote:
| The CEO said
|
| > It's 3M+ lines of code across thousands of files. The rendering
| engine is from-scratch in Rust with HTML parsing, CSS cascade,
| layout, text shaping, paint, and a custom JS VM.
|
| "From scratch" sounds very impressive. "custom JS VM" is as well.
| So let's take a look at the dependencies [1], where we find
|
| - html5ever
|
| - cssparser
|
| - rquickjs
|
| That's just servo [2], a Rust based browser initially built by
| Mozilla (and now maintained by Igalia [3]) but with extra steps.
| So this supposed "from scratch" browser is just calling out to
| code written by humans. And after all that it doesn't even
| compile! It's just plain slop.
|
| [1] -
| https://github.com/wilsonzlin/fastrender/blob/main/Cargo.tom...
|
| [2] - https://github.com/servo/servo
|
| [3] - https://blogs.igalia.com/mrego/servo-2025-stats/
| zipy124 wrote:
| Honestly as soon as I saw browser in rust I assumed it had just
| reproduced the servo source code in part, or utilised its
| libraries.
| nindalf wrote:
| I thought they'd plagiarise, not import. Importing servo's
| code would make it obvious because it's so easy to look at
| their dependencies file. And yet ... they did. I really think
| they thought no one would check?
| satvikpendem wrote:
| > _And yet ... they did. I really think they thought no one
| would check?_
|
| I doubt even _they_ checked, given they say they just let
| the agents run autonomously.
| bonesss wrote:
| Hypothetically: what if they did check, only in order to
| 'check' they asked the LLM instead of manually verifying
| and were told a story? Or, perhaps, they did check
| manually but sometime after the files were subtly changed
| despite no incentive or reason to do so outside of a
| passing test? ...
|
| Humans who are bad and also bad at coding have
| predictable, comprehensible, failure modes. They don't
| spontaneously sabotage their career and your project
| because Lord Markov twitched one of its many tails. They
| also lie for comprehensible reasons with attempts at
| logical manipulations of fact. They don't spontaneously
| lie claiming not to having a nose, apologize for lying
| and promise to never do it again, then swear they have no
| nose in the next breath while maintaining eye contact.
|
| Semi-autonomous to autonomous is a doozy of a step.
| dormento wrote:
| You know, a good test would be to tell it to write a browser
| using a custom programming language, or at least some
| language for which there are no web browsers written.
| embedding-shape wrote:
| Write a browser without any access to the internet, is what
| I'd attempted if I was running this experiment. Just seed
| it with a bunch of local HTML, CSS and JS files from the
| various testing suites that exists.
| koolala wrote:
| You would want to download all the W3C and WHATWG
| specifications first.
| shermantanktop wrote:
| Some of them practically have pseudocode just waiting to
| be picked up.
| computerex wrote:
| I think that's too restrictive; agents should be allowed
| to reference the internet like we do.
| semi-extrinsic wrote:
| Fortran 90 should fit the bill nicely.
| g947o wrote:
| Sounds like it's finally the time to put my matlab license
| up for good use.
| louthy wrote:
| Good idea, I propose Brainfuck
| nicoburns wrote:
| Also selectors and taffy.
|
| It's also using weirdly old versions of some dependencies (e.g.
| wgpu 0.17 from June 2023 when the latest is 28 released in
| Decemeber 2025)
| satvikpendem wrote:
| That is because I've noticed the AI just edits the version
| management files (package.json, cargo.toml, etc) directly
| instead of using the build tool (npm add, cargo add), so it
| always hallucinates a random old version that's found in its
| training set. I explicitly have to tell the AI to use the
| build tool whenever I use AI.
| bn-l wrote:
| It's interesting that they don't even know this
| notatallshaw wrote:
| I assume lock and dependency files are in the training
| data, so predicting version number tokens have high
| probabilities associated with them.
| computerex wrote:
| I was LITERALLY thinking the other day of a niche tool for
| engineers to help them discover and fix this in the future
| because at the rate I have seen models version lock
| dependencies I thought this is going to be a big problem in
| the future.
| satvikpendem wrote:
| Just use Dependi or similar VSCode extensions, they'll
| tell you if dependencies are outdated.
| mikestorrent wrote:
| Bigger companies have vulnerability and version
| management toolsets like Snyk, Cycode, etc. to help keep
| things up to date at scale across lots of repos.
| ljm wrote:
| You can do prompt injection through versions. The LLM
| would go back to GitHub in its endless attempt to people
| please, but dependency managers would ignore it for being
| invalid.
| solid_fuel wrote:
| No need to build a tool for it, engineers can avoid the
| whole issue by simply avoiding slop-spewing code
| generation tools. Hell, just never allow an LLM to modify
| the dependency configuration - if you want to use a
| library, choose and import it yourself. Like an engineer.
| callc wrote:
| Proposal to not tarnish the good name of actual
| engineers: slopgineers.
|
| Maybe LLemgineers? Slopgrammers?
| f311a wrote:
| Yeah, it's
|
| - Servo's HTML parser
|
| - Servo's CSS parser
|
| - QuickJS for JS
|
| - selectors for CSS selector matching
|
| - resvg for SVG rendering
|
| - egui, wgpu, and tiny-skia for rendering
|
| - tungstenite for WebSocket support
|
| And all of that has 3M of lines!
| avaer wrote:
| To be fair, even if "from scratch" means "download and build
| Chromium", that's still nontrivial to accomplish. And with how
| complicated a modern browser is, you can get into Ship of
| Theseus philosophy pretty fast.
|
| I wouldn't particularly care what code the agents copied, the
| bigger indictment is the code doesn't work.
|
| So really, they failed to meet the bar of "download and build
| Chromium" and there's no point to talk about the code at all.
| koolala wrote:
| The whole point of Servo is its not impossible to use like
| Chromium.
| leerob wrote:
| > The JS engine used a custom JS VM being developed in
| vendor/ecma-rs as part of the browser, which is a copy of my
| personal JS parser project vendored to make it easier to commit
| to.
|
| https://news.ycombinator.com/item?id=46650998
| singron wrote:
| It looks like there are two JS backends: quickjs and vm-js
| (vendor/ecma-rs/vm-js), based on a brief skim of the code.
| There is some logic to select between the two. I have no idea
| if either or both of them work.
| themafia wrote:
| > is just calling out to code written by humans
|
| We at least it's not outright ripping them off like it usually
| does.
| wmf wrote:
| Is it using Servo's layout code or did Cursor write its own
| layout? That's one of the hardest parts.
| brabel wrote:
| Cursor didn't write anything, they used ChatGPT 5.2.
| afishhh wrote:
| It seemingly did but after I saw it define a VerticalAlign
| twice in different files[1][2][3] I concluded that it's
| probably not coherent enough to waste time on checking the
| correctness.
|
| Would be interesting if someone who has managed to run it
| tries it on some actually complicated text layout edge cases
| (like RTL breaking that splits a ligature necessitating re-
| shaping, also add some right-padding in there to spice things
| up).
|
| [1] https://github.com/wilsonzlin/fastrender/blob/main/src/la
| you...
|
| [2] https://github.com/wilsonzlin/fastrender/blob/main/src/la
| you...
|
| [3] Neither being the right place for defining a struct that
| should go into computed style imo.
| nicoburns wrote:
| It's using layout code from my library (Taffy) for Flexbox
| and CSS Grid. Servo uses Taffy for CSS Grid, and another open
| source engine that I work on (Blitz) uses it for Flexbox, CSS
| Grid, Block and float layout.
|
| The older block/inline layout modes seem to be custom code
| that looks to me similar but not exactly the same as Servo
| code. But I haven't compared this closely.
|
| I would note that the AI does not seem to have matched either
| Servo or Blitz in terms of layout: both can layout Google.com
| better than the posted screenshot.
| brabel wrote:
| Why would they think it's a great idea to claim they
| implemented CSS and JS from scratch when the first thing any
| programmer would do is to look at the code and immediately find
| out that they're just using libraries for all of that?! They
| can't be as dumb as thinking no one would've noticed?!
|
| I guess the answer is that most people will see the claim, read
| a couple of comments about "how AI can now write browsers, and
| probably anything else" from people who are happy to take
| anything at face value if it supports their view (or business)
| and move on without seeing any of the later comotion. This
| happens all the time with the news. No one bothers to check
| later if claims were true, they may live their whole lives
| believing things that later got disproved.
| bflesch wrote:
| I'm actually impressed by their ignorance. I could never
| sleep at night knowing my product is built on such brazen
| lies.
|
| Bullshitting and fleecing investors is a skill that needs to
| be nurtured and perfected over the years.
|
| I wonder how long this can go on.
|
| Who is the dumb money here? Are VCs fleecing "stupid" pension
| funds until they go under?
|
| Or is it symptom of a larger grifting economy in the US where
| even the president sells vaporware, and people are just
| emulating him trying to get a piece of the cake?
| moregrist wrote:
| > Why would they think it's a great idea to claim they
| implemented CSS and JS from scratch when the first thing any
| programmer would do is to look at the code and immediately
| find out that they're just using libraries for all of that?!
|
| Programmers were not the target audience for this
| announcement. I don't 100% know who was, but you can kind of
| guess that it was a mix of: VC types for funding, other CEOs
| for clout, AI influencers to hype Cursor.
|
| Over-hyping a broken demo for funding is a tale as old as
| time.
|
| That there's a bit of a fuck-you to us pleb programmers is
| probably a bonus.
| never_inline wrote:
| I don't think he intentionally lied. He just didn't know how
| to check that and AI wrote - [tick mark
| emoji] implemented CSS and JS rendering from scratch - **no
| dependencies**.
| estearum wrote:
| I mean... Cursor is the CEO's first non-internship job. And
| it was a VSCode Extension that caught fire atop the largest
| technological groundswell in a few decades.
|
| The default assumption should be that this is a moderately
| bright, very inexperienced person who has been put _way_ out
| over his skis.
| ben_w wrote:
| That tracks with what I'm seeing.
|
| Unfortunately for them, I've seen things go very very wrong
| in this situation. It's very easy to mistake luck-based
| financial success for skill-based, especially when it
| happens fresh out of university.
| autoexec wrote:
| > They can't be as dumb as thinking no one would've noticed?!
|
| Maybe they're just hoping that there's an investor out there
| who is exactly that dumb.
| ben_w wrote:
| > They can't be as dumb as thinking no one would've noticed?!
|
| With over 20 years of experience as an adult, and more years
| of noticing dumb mistakes of adults when I was a teen, I can
| absolutely assure you that even before LLMs were blowing
| smoke up their user's backsides and flattering their user's
| intelligence, plenty of people are dumb enough to make
| mistakes like this without noticing anything was wrong.
|
| For example, I'm currently dealing with customer support
| people that can't seem to handle two simultaneous requests or
| read the documents they send me, even after being ordered to
| pay compensation by an Ombudsman. This kind of person can, of
| course, already be replaced by an LLM.
| adamrezich wrote:
| Very sad to see Paul Graham boosting this slop on X.
| levocardia wrote:
| I'm reminded of the viral tweet along the lines of "Claude just
| one-shotted a 10k LOC web app from scratch, 10+ independent
| modules and full test coverage. None of it works, but it was
| beautiful nonetheless."
| wilsonzlin wrote:
| Thanks for the feedback. I've addressed similar feedback at [0]
| and provided some more context at [1].
|
| I do want to briefly note that the JS VM is custom and not
| QuickJS. It also implemented subsystems like the DOM, CSS
| cascade, inline/block/table layouts, paint systems, text
| pipeline, and chrome, and I'd push back against the assertion
| that it merely calls out to external code. I addressed these
| points in more detail at [0].
|
| [0] https://news.ycombinator.com/item?id=46650998 [1]
| https://news.ycombinator.com/item?id=46655608
| nindalf wrote:
| > I do want to briefly note that the JS VM is custom and not
| QuickJS
|
| It's hard to verify because your project didn't actually
| compile. But now that you've fixed the compilation manually,
| can you demonstrate the javascript actually executing? Some
| of the people who got the slop compiling claimed credibly
| that it isn't executing any JavaScript.
|
| You merely have to compile your code, run the binary and open
| this page - http://acid3.acidtests.org. Feel free to post a
| video of yourself doing this. Try to avoid the embellishment
| that has characterised this effort so far.
| Snuggly73 wrote:
| This is from the "official" build -
| https://imgur.com/fqGLjSA
|
| The "in progress" build has a slightly different rendering
| but the same result
| nindalf wrote:
| Yeah, it's not executing any JavaScript. Hey Mr. Wilson!
| You've spent millions creating this worthless slop. How
| about making sure that the code is actually being
| executed? Or is that not necessary to raise millions more
| in VC funding?
| user432678 wrote:
| Are you telling me AI bros lying about their products? No way
| that ever happened...
| m00dy wrote:
| Cursor CEO got grilled in HN for a good reason.
| deng wrote:
| If you look at the original Cursor post, they say they are
| currently running similar experiments, for instance, this Excel
| clone:
|
| https://github.com/wilson-anysphere/formula
|
| The Actions overview is impressive: There have been 160,469
| workflow runs, of which 247 succeeded. The reason the workflows
| are failing is because they have exceeded their spending limit.
| Of course, the agents couldn't care less.
| felipeerias wrote:
| IMHO people are missing the forest for the trees. The point of
| this experiment is not to build a functional browser but to
| develop ways to make agents create large codebases from scratch
| over a very long time span. A Web browser is just a convenient
| target because there are lots of documentation, specs and tests
| available.
| noodletheworld wrote:
| ...but it didn't develop ways of doing that did it?
|
| Any idiot can have cursor run for 2 weeks and produce a pile
| of crap that doesn't compile.
|
| You know the brilliant insight they came out with?
|
| > A surprising amount of the system's behavior comes down to
| how we prompt the agents. Getting them to coordinate well,
| avoid pathological behaviors, and maintain focus over long
| periods required extensive experimentation. The harness and
| models matter, but the prompts matter more.
|
| i.e. It's kind of hard and we didn't really come up with a
| better solution than 'make sure you write good prompts'.
|
| Wellll, geeeeeeeee! Thanks for that insight guys!
|
| Come on. This was complete BS. Planners and workers. Cool.
| Details? Any details? Annnnnnnyyyyy way to replicate it? What
| sort of prompts did you use? How did you solve the
| pathalogical behaviours?
|
| Nope. The vagueness in this post... it's not an experiment.
| It's just fund raising hype.
| chrisandchris wrote:
| IMHO, this whole thing could be read with "human" instread
| of "agent" and would make the exact same amount of sense.
|
| "We put 200 human in a room and gave them instructions how
| to build a browser. They coded for hours, resolving merge
| conflicts and producing code that did not build in the end
| without intervention of seniors [ _]. We think, giving them
| better instructions leads to better results "
|
| So they actually invented humans? And will it come down to
| either "managing humans" or "managing agents"? One of both
| will be more reliable, more predictable and more convenient
| to work with. And my guess is, it is not an agent...
|
| _ As it seemed in the git log, something is weird.
| saghm wrote:
| The point is to learn how to make very large codebases that
| don't compile? Why do you need tests and specs if it's not
| going to even run, much less run correctly?
| felipeerias wrote:
| As discussed elsewhere, it is apparently possible to
| compile and run this particular project. It seems that
| whatever process they followed allows commits to break the
| build pretty often.
|
| Nevertheless, IMHO what's interesting about this is not the
| browser itself but rather that AI companies (not just
| Cursor) are building systems where humans can be out of the
| loop for days or weeks.
| embedding-shape wrote:
| > As discussed elsewhere, it is apparently possible to
| compile and run this particular project.
|
| After a human stepped in to fix it, yes. You can see it
| yourself here:
| https://github.com/wilsonzlin/fastrender/issues/98
|
| > Nevertheless, IMHO what's interesting about this is not
| the browser itself but rather that AI companies (not just
| Cursor) are building systems where humans can be out of
| the loop for days or weeks.
|
| But that's not what they demonstrated here. What they
| demonstrated, so far, is that you can let agents write
| millions of lines of code, and eventually if you actually
| need to run it, some human need to "merge the latest
| snapshot" or do some other management to actually put
| together the system into a workable state.
|
| Very different from what their original claims were.
| thegeomaster wrote:
| I actually ran this one. It measures some 700k lines of code,
| and seems to contain things like a full VBA implementation,
| complex currency and date parsing, etc. But the UI is extremely
| basic, doesn't seem to expose any of this advanced
| functionality, and and is buggy to the point of being unusable.
| Focus will jump around as you type, cells will reset to old
| values, it will stop responding to keyboard events, etc.
| Matthyze wrote:
| Out of curiosity, what is the most difficult thing about building
| a browser?
| MobiusHorizons wrote:
| The very long task list.
|
| Browsers contain several high complexity pieces each of could
| take a while to build on its own, and interconnect them with
| reasonably verbose APIs that need to be implemented or at least
| stubbed out for code to not crash. There is also the difficulty
| of matching existing implementations quirk for quirk.
|
| I guess the complexity is on-par with operating systems, but
| with the added compatibility problems that in order to be
| useful it doesn't just have to load sites intended to be
| compatible with it, it has to handle sites people actually use
| on the internet, and those are both a moving target, and tend
| to use lots of high complexity features that you have to build
| or at least stub out before the site will even work.
| asadotzler wrote:
| In all sincerity, this question is almost identical to "what's
| the most difficult thing about building an operating system" as
| a modern browser is tens of millions of lines of code that can
| run sophisticated applications. It has a network stack, half a
| dozen parsers, frame construction and reflow modules,
| composite, render and paint components, front end UI
| components, an extensibility framework, and more. Each one of
| these must enable supporting backward compatibility for 30 year
| old content as well as ridiculously complex contemporary web
| apps. And it has to load and render sites that a completely
| programming illiterate fool like me wrote. It must do this all
| in a performant and secure way using minimal system resources.
| Also, it probably also must run on Mac, Windows, Linux,
| Android, iOS, and maybe more.
| potamic wrote:
| Check out the list of all CSS specifications [1], and then open
| any one of them and see how lengthy and elaborate each is. Then
| do the same for each version of the spec published over the
| last thirty years. Before you can start, you must read and
| understand all of this at a great level of depth. Still,
| specifications never tell the complete story. You must be aware
| of all the nuances that are implied by each requirement in the
| spec and know how to handle the zillion corner cases that will
| crop up inevitably.
|
| And this is just one part. Not even considering the fully
| sandboxed, mini operating system for running webapps.
|
| [1] https://www.w3.org/Style/CSS/specs.en.html
| Pinus wrote:
| I haven't studied the project that this is a comment on, but: The
| article notices that something that compiles, runs, and renders a
| trivial HTML page might be a good starting point, and I would
| certainly agree with that when it's humans writing the code. But
| is it the _only_ way? Instead of maintaining "builds and runs" as
| a constant and varying what it does, can it make sense to have "a
| decent-sized subset of browser functionality" as a constant and
| varying the "builds and runs" bit? (Admittedly, that bit does not
| seem to be converging here, but I'm curious in more general
| terms.)
| madeofpalk wrote:
| ...What use is code if it doesn't build and run? What other way
| is there to build a browser that doesn't involved 'build and
| run'?
|
| Writing junk in a text file isn't the hard part.
| Pinus wrote:
| Obviously, it has to _eventually_ build and run if there's to
| be any point to it, but is it necessary that every, or even
| any, step along the way builds and runs? I imagine some sort
| of iterative set-up where one component generates code, more
| or less "intelligently", and others check it against the C,
| HTML, JavaScript, CSS and what-have-you specs, and the whole
| thing iterates until all the checking components are happy.
| The components can't be completely separate, of course,
| they'd have to be more or less intermingled or convergence
| would be very slow (like when lcamtuf had his fuzzer generate
| a JPEG out of an empty file), but isn't that basically what
| (large) neural networks are; tangled messes of interconnected
| functions that do things in ways too complicated for anyone
| to bother figuring out?
| malfist wrote:
| How do you iteratively improve a broken codebase that
| doesn't compile with more than 3 million lines of code?
| brabel wrote:
| I don't want to defend the AI slop, but it's common for
| me to go on for a few weeks without being able to compile
| everything when doing something realy big. I can still
| compile individual modules and run their tests, but not
| the full application (which puts all modules together)...
| but it may take a lot of time until all modules can come
| together and actually run the app.
| fwip wrote:
| Human brains are big, tangled messes of interconnected
| neurons that do things in way too complicated to figure
| out.
|
| That doesn't mean we can usefully build software that is a
| big, tangled mess.
| johntb86 wrote:
| In theory you could generate a bunch of code that seems mostly
| correct and then gradually tweak it until it's closer and
| closer to compiling/working, but that seems ill-suited to how
| current AI agents work (or even how people work). AI agents are
| prone to make very local fixes without an understanding of
| wider context, where those local fixes break a lot of
| assumptions in other pieces of code.
|
| It can be very hard to determine if an isolated patch that goes
| from one broken state to a different broken state is on net an
| improvement. Even if you were to count compile errors and
| attempt to minimize them, some compile errors can demonstrate
| fatal flaws in the design while others are minor syntax issues.
| It's much easier to say that broken tests are very bad and
| should be avoided completely, as then it's easier to ensure
| that no patch makes things worse than it was before.
| eloisius wrote:
| > generate a bunch of code that seems mostly correct and then
| gradually tweak it until it's closer and closer to
| compiling/working
|
| The diffusion model of software engineering
| rsynnott wrote:
| > an it make sense to have "a decent-sized subset of browser
| functionality" as a constant and varying the "builds and runs"
| bit?
|
| I mean by definition something that doesn't build and run
| doesn't have any browser-like functionality at all.
| thedelanyo wrote:
| These are stories that solely exist just to sell shovels and
| would cause one uninformed CEO to layoff actual humans.
| AIorNot wrote:
| Lesson 1:
|
| Always take any pronouncement from an AI company (heavily
| dependent on VC and public sentiment on AI) with a heavy grain of
| salt..
|
| hype over reality
|
| I'm building an AI startup myself and I know that world and its
| full of hypsters and hucksters unfortunately - also social media
| communication + low attention span + AI slop communication is a
| blight upon todays engineering culture
| Snuggly73 wrote:
| The latest commit now builds _and_ runs (at least on my Mac).
| It's tragically broken and the code is...dunno...something. 3m
| lines of something.
|
| I couldn't make it render the apple page that was on the Cursor
| promo. Maybe they've used some other build.
| embedding-shape wrote:
| Yeah, seems latest commit does let `cargo check` successfully
| run. I'm gonna write an update blog post once they've made
| their statement, because I'm guessing they're about to say
| something.
|
| Sometime fishy is happening in their `git log`, it doesn't seem
| like it was the agents who "autonomously" actually made things
| compile in the end. Notice the git username and email addresses
| switching around, even some commits made inside a EC2 instance
| managed to get in there: https://gist.github.com/embedding-
| shapes/d09225180ea3236f180...
| Snuggly73 wrote:
| Noticed that as well - I think it was "manual"
| torginus wrote:
| I am not an expert AI user, but one typical 'failure mode' I
| see constantly is the AI reimplementing features that already
| exist in the codebase, or breaking existing ones.
| lifetimerubyist wrote:
| > company claims they "built a browser" from scratch
|
| > looks inside
|
| > completely useless and busted
|
| 30 billion dollar VS Code fork everyone. When we do start looking
| at these people for what they are: snake oil salesmen.
|
| They slop laundered the FOSS Servo code into a broken mess and
| called it a browser, but dumbasses with money will make line go
| up based on lies. EFF right off.
| bn-l wrote:
| 30. Billion. Dollars.
|
| Man
| lifetimerubyist wrote:
| It's absolutely absurd.
| ben_w wrote:
| When I tried it last year, the mac download of this particular
| VS Code fork was only available as an Intel build. This... was
| suggestive.
| pavlov wrote:
| The comment that points out that this week-long experiment
| produced nothing more than a non-functional wrapper for Servo (an
| existing Rust browser) should be at the top:
|
| https://news.ycombinator.com/item?id=46649046
| pera wrote:
| Has anyone tried to rewrite some popular open source project
| with IA? I imagine modern LLMs can be very effective at
| license-washing/plagiarizing dependencies, it could be an
| interesting new benchmark too
| benhoyt wrote:
| Not me personally, but a GitHub user wrote a replacement for
| Go's regexp library that was "up to 3-3000x+ faster than
| stdlib": https://github.com/coregx/coregex ... at first I was
| impressed, so started testing it and reporting bugs, but as
| soon as I ran my own benchmarks, it all fell apart
| (https://github.com/coregx/coregex/issues/29). After some
| mostly-bot updates, that issue was closed. But someone else
| opened a very similar one recently
| (https://github.com/coregx/coregex/issues/79) -- same deal,
| "actually, it's slower than the stdlib in my tests".
| Basically AI slop with poor tests, poor benchmarks, and way
| oversold. How he's positioning these projects is the
| problematic bit, I reckon, not the use of AI.
|
| Same user did a similar thing by creating an AWK interpreter
| written in Go using LLMs: https://github.com/kolkov/uawk --
| as the creator of (I think?) the only AWK interpreter written
| in Go (https://github.com/benhoyt/goawk), I was curious. It
| turns out that if there's only one item in the training data
| (GoAWK), AI likes to copy and paste freely from the original.
| But again, it's poorly tested and poorly benchmarked.
|
| I just don't see how one can get quality like this, without
| being realistic about code review, testing, and benchmarking.
| CuriouslyC wrote:
| To be fair, good benchmarking is hard, most people get it
| wrong. Scientific training helps.
| dragonwriter wrote:
| > up to 3-3000x+ faster than stdlib
|
| Note that this is semantically exactly equivalent to "up to
| 3000x faster than stdlib" and doesn't actually claim any
| particular actual speedup since "up to" denotes an upper
| bound, not a lower bound or expected value. It's standard
| misleading-but-not-technically-false marketing language to
| create a false impression because people tend to focus on
| the number and ignore the "up to".
| supriyo-biswas wrote:
| Reminds me of https://xkcd.com/870/
| arcticbull wrote:
| With the "up to 3-3000x+" language the plus leaves us
| with the entire number line.
| Dylan16807 wrote:
| When you say "up to" about a list of data points, it's
| not just a bound. At least one has to reach that amount
| or it's a lie.
| nkrisc wrote:
| Saying "up to" means that bound is the maximum value of
| the data set. It may be far from the median value, but it
| is included (or you're lying). With any other
| interpretation the phrase has no meaning whatsoever.
| nkrisc wrote:
| I will concede, proactively, that "up to" could refer to
| some maximum possible bound, even if the current set
| doesn't include a value at that bound, though I would
| argue that's likely deceptive wording. For example, you
| could say that each carton of of eggs on a pallet
| contains up to 12 eggs, because that's the maximum
| capacity of the carton, even if none of the actual
| cartons on this pallet actually have 12 eggs in them.
| DonHopkins wrote:
| 3000x Faster Optimized Random Number Generator:
| https://xkcd.com/221/
| gorkaerana wrote:
| I think it's fair enough to consider porting a subset of
| rewriting, in which case there are several successful
| experiments out there:
|
| - JustHTML [1], which in practice [2] is a port of html5ever
| [3] to Python.
|
| - justjshtml, which is a port of JustHTML to JavaScript :D
| [4].
|
| - MiniJinja [5] was recently ported to Go [6].
|
| All three projects have one thing in common: comprehensive
| test suites which were used to guardrail and guide AI.
|
| References:
|
| 1. https://github.com/EmilStenstrom/justhtml
|
| 2. https://friendlybit.com/python/writing-justhtml-with-
| coding-...
|
| 3. https://github.com/servo/html5ever
|
| 4. https://simonwillison.net/2025/Dec/15/porting-justhtml/
|
| 5. https://github.com/mitsuhiko/minijinja
|
| 6. https://lucumr.pocoo.org/2026/1/14/minijinja-go-port/
| daxfohl wrote:
| Interesting, IIUC the transformer architecture / attention
| mechanism were initially designed for use in the language
| translation domain. Maybe after peeling back a few layers,
| that's still all they're really doing.
| nathan_compton wrote:
| This has long been how I have explained LLMs to non-
| technical people: text transformation engines. To some
| extent, many common, tedious, activities basically
| constitute a transformation of text into one well known
| form from another (even some kinds of reasoning are this)
| and so LLMs are very useful. But they just transform text
| between well known forms.
| daxfohl wrote:
| And while it appears that lots of problems can be
| contorted into translation, "if all you have is a hammer,
| everything looks like a nail". Maybe we do hit a brick
| wall unless we can come up with a model that more closely
| aligns with actual human reasoning.
| EmilStenstrom wrote:
| As the author, it's a stretch to say that JustHTML is a
| port of html5ever. While you're right that this was part of
| the initial prompt, the code is very different, which is
| typically not what counts as "port". Your mileage may wary.
| MrJohz wrote:
| Note that it's not clear that any of the JustHTML ports
| were actually ports per se, as in the end they all ended up
| with very different implementations. Instead, it might just
| be that an LLM generated roughly the same library several
| different times.
|
| See https://felix.dognebula.com/art/html-parsers-in-
| portland.htm...
| DonHopkins wrote:
| More vibe coded browser modules:
|
| V8 => H8 - JavaScript engine that hates code,
| misunderstands equality, sponsored by Brendan Eich and "Yes
| on Prop H8".
|
| Expat => Vexpat - An annoying, irritating rewrite of an XML
| parser.
|
| libxml2 => libxmlpoo - XML parsing, same quality as the
| spec.
|
| libxslt => libxsalt - XSLT transforms with extra salt in
| the wound.
|
| Protobuf => Probabuf - Probably serializes correctly,
| probably not, fuzzy logic.
|
| Cap'n Proto => Crap'n Proto - Zero-copy, zero quality.
|
| cURL => cHURL - Throws requests violently serverward,
| projectile URLemitting.
|
| SDL => STD - Sexually Transmitted Dependency. It never
| leaves and spreads bugs to everything you touch.
|
| Servo => Swervo - Drunk, wobbly layout that can't stay on
| the road.
|
| WebKit => WebShite - British pronunciation, British quality
| control.
|
| Blink => Blinkered - Only renders pages it agrees with
| politically.
|
| Taffy => Daffy - Duck typed Flexbox layout that's
| completely unhinged. "You're dethpicable!"
|
| html5ever => html5never - Servo's HTML parser that never
| finishes tokenizing.
|
| Skia => SkAI - AI-generated graphics that hallucinates
| extra pixels and fingers.
|
| FreeType => FreeTypo - Introduces typos during keming and
| rasterization.
|
| Firefox => Foxfire - Burns through your battery in 12
| minutes, while molesting children.
|
| WebGL => WebGLitch - Shader compilation errors as art.
|
| WebGPU => WebGPUke - Makes your GPU physically ill.
|
| SQLite => SQLHeavy - Embedded database, 400MB per query.
|
| Vulkan => Vulcan't - Low-level graphics that can't.
|
| Clang => Clanger - Drops errors loudly at runtime.
|
| libevent => liebevent - Event library that lies about
| readiness.
|
| Opus => Oops - Audio codec, "oops, your audio's gone."
|
| All modules now available on GitPub:
|
| GitHub => GitPub - Microsoft's vibe control system
| optimized for the Ballmer Peak. Commit quality peaks at
| 0.129% BAC, mass reverts at 0.15%.
| hedgehog wrote:
| I used one of the assistants to reverse and rewrite a
| browser-hosted JS game-like app to desktop Rust. It required
| a lot of steering but it was pretty useful.
| quotemstr wrote:
| Negative results are great. When you publish them on purpose,
| it's honorable. When you reveal them by accidentally, it's
| hilarious. Cheers to Cursor for today's entertainment.
| gjsman-1000 wrote:
| What the hell?
|
| I was seeing screenshots and actually getting scared for my job
| for a second.
|
| It's broken and there's no browser engine? Cursor should be
| tarred and feathered.
| autoexec wrote:
| A lie like this seems like it should be considered fraud
| AstroBen wrote:
| Apparebtly this person actually got it to compile:
| https://xcancel.com/CanadaHonk/status/2011612084719796272#m
| observationist wrote:
| https://x.com/CanadaHonk/status/2011612084719796272 as well.
|
| I went through the motions. There are various points in the
| repo history where compilation is possible, but it's obscure.
| They got it to compile and operate prior to the article, but
| several of the PRs since that point broke everything, and
| this guy went through the effort of fixing it. I'm pretty
| sure you can just identify the last working commit and pull
| the version from there, but working out when looks like a big
| pain in the butt for a proof of concept.
| embedding-shape wrote:
| > but several of the PRs since that point broke everything,
| and this guy went through the effort of fixing it. I'm
| pretty sure you can just identify the last working commit
| and pull the version from there, but working out when looks
| like a big pain in the butt for a proof of concept.
|
| I went through the last 100 commits
| (https://news.ycombinator.com/item?id=46647037) and nothing
| there was working (yet/since). Seems now after a developer
| corrected something it managed to pass `cargo check`
| without errors, since commit
| 526e0846151b47cc9f4fcedcc1aeee3cca5792c1 (Jan 16 02:15:02
| 2026 -0800)
| observationist wrote:
| There are conversations elsewhere - I'd have to go look
| through them, but at some point about an hour before the
| article was published, it could be compiled, and then
| things got pushed that broke it again? There's no central
| discussion, I had to piece together information from
| multiple threads.
|
| Sorry, I should have taken notes, lol. At any rate, it
| was so much digging around I just gave up, I didn't want
| to invest more effort into it. I figured they'd get a
| stable version for others to try and I'd return to it at
| some point.
| mvdtnz wrote:
| Why is the top comment on this item just a link to another
| comment on this same story?
| M4v3R wrote:
| It's not just a wrapper for Servo, the linked poster just
| checked the dependencies in the Cargo file and proclaimed that
| without checking anything further.
|
| In reality this project does indeed implement a functioning
| custom JS Engine, Layout engine, painting etc. It does borrow
| the CSS selectors package from Servo but that's about it.
| oefrha wrote:
| Yeah there's more to a browser than a couple of out-of-tree
| servo components, otherwise https://github.com/servo/servo
| wouldn't have 300k+ lines of Rust code, 400k+ if you count
| comments and blanks (I cloned the repo, nuked the tests
| directory, then did a count).
|
| Plus that linked comment doesn't even say it's "nothing more
| than a non-functional wrapper for Servo". It disputes the
| "from scratch" claim.
|
| Most people aren't interested in a nuanced take though.
| Someone said something plausible sounding and was voted to
| top by other people? Good enough for me, have another vote.
| Then twist and exaggerate a little and post it to another
| comment section. Get more votes. Rinse and repeat.
| pera wrote:
| "Borrow" is an interesting choice of word, see for example
| this: /// The quirks mode of the document.
| #[inline] pub fn quirks_mode(&self) -> QuirksMode {
| self.quirks_mode }
|
| https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645.
| ..
|
| And then this: /// The quirks mode of the
| document. pub fn quirks_mode(&self) -> QuirksMode {
| self.stylist.quirks_mode() }
|
| https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a.
| ..
|
| It seems ChatGPT is still copying segments of code almost
| verbatim, although sometimes it does weird things, compare
| these for example:
|
| https://github.com/wilsonzlin/fastrender/blob/3e5bc78b075645.
| ..
|
| https://github.com/servo/stylo/blob/71737ad5c8b29c143a6c992a.
| ..
| torginus wrote:
| Interesting, I remembered that when trying out Stable
| Diffusion, once I ventured outside of the realm of anime
| waifus, the images ended up being so similar to existing
| sources, that image search could find the references.
|
| Which is also kinda crazy since superficially there was
| very little similar between the 2 images, but I guess AI
| models used for image search converge on similar embedding
| than the ones used for AI generation.
| Snuggly73 wrote:
| Well, could it be because it was instructed to kinda
| "study" Servo?
|
| https://github.com/wilsonzlin/fastrender/blob/3e5bc78b07564
| 5...
| nindalf wrote:
| In your hurry to defend this slop you didn't do your due
| diligence. You know that 1 million LoC JS VM? Yeah, it isn't
| actually running - https://imgur.com/fqGLjSA. And you can
| tell this is actually the case because it's been brought up a
| few times on this thread and that guy has ducked around it.
| wilsonzlin wrote:
| I've responded to this claim in more detail at [0], with
| additional context at [1].
|
| Briefly, the project implemented substantial components,
| including a JS VM, DOM, CSS cascade, inline/block/table layout,
| paint systems, text pipeline, and chrome, and is not merely a
| Servo wrapper.
|
| [0] https://news.ycombinator.com/item?id=46650998
|
| [1] https://news.ycombinator.com/item?id=46655608
| embedding-shape wrote:
| Could you somewhere make clear exactly how much of the code
| was "autonomously" built vs how much was steered by humans?
| Because at this point it's clear that it wasn't 100%
| autonomous as originally claimed, but right now it's not
| clear if this was just the work of an engineer running Cursor
| vs "autonomously organised a fleet of agents".
| pera wrote:
| Just for context, this was the original claim by Cursor's CEO
| on Twitter:
|
| > _We built a browser with GPT-5.2 in Cursor. It ran
| uninterrupted for one week._
|
| > _It 's 3M+ lines of code across thousands of files. The
| rendering engine is from-scratch in Rust with HTML parsing,
| CSS cascade, layout, text shaping, paint, and a custom JS
| VM._
|
| > _It kind of works! It still has issues and is of course
| very far from Webkit /Chromium parity, but we were astonished
| that simple websites render quickly and largely correctly._
|
| https://xcancel.com/mntruell/status/2011562190286045552#m
| delusional wrote:
| I cannot make these two statements true at the same time in
| my head:
|
| > Briefly, the project implemented substantial components,
| including a JS VM
|
| and from the linked reply:
|
| > vendor/ecma-rs as part of the browser, which is a copy of
| my personal JS parser project vendored to make it easier to
| commit to.
|
| If it's using a copy of your personal JS parser that you
| decided it should use, then it didn't implement it
| "autonomously". The references you're linking don't summarize
| to the brief you've provided.
|
| What the fuck is going on?
| nonima wrote:
| It's funny how their whole grift hinges on people not
| reading clearly.
| Roark66 wrote:
| Does any of it actually work? Can you build that JS VM
| separately and run serious JS on it? That would be an
| accomplishment.
|
| Looking at the comments and claims (I've not got the time to
| review a large code base just to check this claim) I get an
| impression _something_ was created, but none of it actually
| builds and no one knows what is the actual plan.
|
| Did your process not involve recursive planning stages (these
| ALWAYS have big architectural error and gotchas in my
| experience, unless you're doing a small toy project or
| something the AI has seen thousands of already).
|
| I find agents doing pretty well once you have a human correct
| their bad assumptions and architectural errors. But this
| assumes the human has absolute understanding of what is being
| done down to the tiniest component. There will be errors
| agents left to their own will discover at the very end after
| spending dozens of millions of tokens, then they will try the
| next idea they hallucinated, spend another few dozen million
| tokens and so on. Perhaps after 10 iterations like this they
| may arrive at something fine or more likely they will descent
| into hallucinations hell.
|
| This is what happens when one of :the complexity, the size,
| or it being novel enough (often a mix of all 3) of the task
| exceed the capability of the agents.
|
| The true way to success is the way of a human-ai hybrid, but
| you absolutely need a human that knows their stuff.
|
| Let me give you a small example from systems field. The other
| day I wanted to design an AI observability system with the
| following spec: - use existing OS components, none or as
| little code as possible - ideally runs on stateless pods on
| an air gapped k3s cluster (preferably uses one of existing
| DBs, but clickhouse acceptable) - able to proxy openai,
| anthropic(both api and clause max), google(vercel+gemini),
| deepinfra, openrouter including client auth (so it is
| completely transparent to the client) - reconstruct streaming
| responses, recognises tool calls, reasoning content, nice to
| have ability to define own session/conversation recognition
| rules
|
| I used gemini 3 and opus 4.5 for the initial
| planning/comparison of os projects that could be useful. Both
| converged on helicone as being supposedly the best. Until
| towards the very end of implementation it was found helicone
| has pretty much zero docs for properly setting up self hosted
| platform, it tries redirecting to their Web page for auth and
| agents immediately went into rewriting parts of the source
| attempting to write their own auth/fixing imaginary bugs that
| were really miscondiguration.
|
| Then another product was recommended (I forgot which), there
| upon very detailed questioning, requesting re-confirmations
| of actual configs for multiple features that were supposedly
| supported it turned out it didn't pass through auth for
| clause max.
|
| Eventually I chose litellm+langfuse (that was turned down
| initially in favour of helicone) and I needed to make few
| small code changes so Claude max auth could be read,
| additional headers could be passed through and within a
| single endpoint it could send Claude telemetry as pure pass
| through and real llm api through it's "models" engine (so it
| recognised tool calls and so on).
| csomar wrote:
| Did you actually review these implementations and compare
| them to Servo (and WebKit)? Can you point to a specific part
| or component that was fully created by the LLM but doesn't
| clearly resemble anything in existing browser engines?
| nindalf wrote:
| You're claiming that the JS VM was implemented. Is it
| actually running? Because this screenshot shows that the
| ACID3 benchmark is requesting that you enable JavaScript
| (https://imgur.com/fqGLjSA). Why don't you upload a video of
| you loading this page?
|
| Your slop is worthless except to convince gullible investors
| to give you more money.
| holoduke wrote:
| A bit off topic, but fun for people having lots of Claude
| credits. Auto Claude is a nice opensource repo to let Claude
| generate entire application from just one prompt. Lots of Jolo
| vibing her, but nevertheless impressive. Last week I asked it
| in one sentence to create a full blown Hotel website including
| all the software tools for backoffice. It took almost 4 days
| with 4 Claude accounts. It actually created a working thing.
| chaosprint wrote:
| I really doubt this marketing approach is effective. Isn't this
| just shooting themselves in the foot? My actual experience with
| Cursor has been: their design is excellent and the UX is great--
| it handles frontend work reasonably well. But as soon as you go
| deeper, it becomes very prone to serious bugs. While the addition
| of Claude's new models has helped somewhat, the results are still
| not as good as Google's Antigravity (despite its poor UX and
| numerous bugs). What's worse, even with this much-hyped Claude
| model, you can easily blow through the $20 subscription limit in
| just a few days. Maybe they're betting on models becoming 10x
| better and 10x cheaper, but that seems unlikely to happen anytime
| soon.
| bonesss wrote:
| Hitting my head into buggy apps made by these AI companies and
| seeing them all be amazed in parallel that skills/MCP would be
| necessary for real work has me pretty relaxed about 'our jobs'.
|
| OpenAIs business-model floundering, degenerating inline to ads
| soon (lol), shows what can be done with infini-LLM, infini-
| capital, and all the smarts & connections on Earth... broadly
| speaking, I think the geniuses at Google who invented a lot of
| this shizz understand it and were leveraging it appropriately
| before ChatGPT blew up.
| thewhitetulip wrote:
| We use mcp at work. Due to some typo the model ran absolutely
| random queries on our database most of the cases. We had
| initially kept ot open ended but after that, we wrote custom
| tools that took an input, gave an output and that was
| strictly mentioned in the prompt. Only then did it work fine.
| ryanisnan wrote:
| The amount of negativity in the original post was astounding.
|
| People were making all sorts of statements like: - "I cloned it
| and there were loads of compiler warnings" - "the commit build
| success rate was a joke" - "it used 3rd party libs" - "it is AI
| slop"
|
| What they all seem to be just glossing over is how the project
| unfolded: without human intervention, using computers, in an
| exceptionally accelerated time frame, working 24hr/day.
|
| If you are hung up on commit build quality, or code quality, you
| are completely missing the point, and I fear for your job
| prospects. These things will get better; they will get safer as
| the workflows get tuned; they will scale well beyond any of us.
|
| Don't look at where the tech is. Look where it's going.
| embedding-shape wrote:
| As mentioned elsewhere (I'm the author of this blogpost), I'm a
| heavy LLM user myself, use it everyday as a tool, get lots of
| benefits from it. It's not a "hit post" on using LLM tools for
| development, it's a post about Cursor making grand claims
| without being able to back them up.
|
| No one is hung up on the quality, but there is a ground fact if
| something "compiles" or "doesnt". No one is gonna claim a
| software project was successful if the end artifact doesn't
| compile.
| ryanisnan wrote:
| I think for the point of the article, it appeared to, at some
| point, render homepages for select well known sites. I
| certainly did not expect this to be a serious browser, with
| any reliability or legs. I don't think that is dishonest.
| embedding-shape wrote:
| > I certainly did not expect this to be a serious browser,
| with any reliability or legs.
|
| Me neither, and I note so twice in the submission article.
| But I also didn't expect a project that for the last 100+
| commits couldn't reliably be built and therefore tested and
| tried out.
| ryanisnan wrote:
| My apologies - my point(s) were more about the original
| submission for the Cursor blog post, not your post
| itself.
|
| I did read your post, and agree with what you're saying.
| It would be great if they pushed the agents to favour
| reliability or reproducibility, instead of just marching
| forwards.
| svieira wrote:
| > What they all seem to be just glossing over is how the
| project unfolded: without human intervention, using computers,
| in an exceptionally accelerated time frame, working 24hr/day.
|
| Correct, but Gas Town [1] already happened and what's more
| _actually worked_, so this experiment is both useless (because
| it doesn't demonstrate working software) _and_ derivative
| (because we've already seen that you can set up a project where
| with spend similar to the spend of a single developer you can
| churn out more code than any human could read in a week).
|
| [1]: https://github.com/steveyegge/gastown
| serial_dev wrote:
| It is hard to look at where it is going when there are so many
| lies about where the tech is today. There are extraordinary
| claims made on Twitter all the time about the technology, but
| when you look into things, it's all just smoke and mirrors, the
| claims misrepresent the reality.
| jcims wrote:
| People that spend time poking holes in random vendor claims
| remind me of folks you see video of standing on the beach
| during a tsunami warning. Their eyes fixed on the horizon
| looking for a hundred foot wave, oblivious to the shore in
| front of them rapidly being gobbled up by the sea.
| gordonhart wrote:
| > oblivious to the shore in front of them rapidly being
| gobbled up by the sea
|
| Am I misunderstanding this metaphor? Tsunamis pull the sea
| _back_ before making landfall.
| alfalfasprout wrote:
| What a silly take. Where the tech is is extremely relevant. The
| reality of this blog post is it shows the tech is clearly not
| going anywhere better either, as they seem to imply. 24 hours
| of useless code is still useless code.
|
| This idea that quality doesn't matter is silly. Quality is
| critical for things to work, scale, and be extensible. By
| either LLMs or humans.
| malfist wrote:
| >If you are hung up on commit build quality
|
| I'm sorry but what? Are you really trying to argue that it
| doesn't matter that nothing works, that all it produced is
| garbage and that what is really important is that it made that
| garbage really quickly without human oversight?
|
| That's.....that's not success.
| ryanisnan wrote:
| Quality absolutely matters, but it's hyper context dependent.
|
| Not everything needs to, or should have the same quality
| standards applied to them. For the purposes of the Cursor
| post, it doesn't bother me that most of the commits produced
| failed builds. I assume, from their post, that at some
| points, it was capable of building, and rendering the pages
| shown in the video on the post. That alone, is the thing that
| I think is interesting.
|
| Would I use this browser? Absolutely not. Do I trust the
| code? Not a chance in hell. Is that the point? No.
| malfist wrote:
| "Quality" here isn't if A is better than B. It's "Does this
| thing actually work at all?"
|
| Sure, I don't care too much if the restaurant serves me
| food with silverware that is 18/10 vs 18/0 stainless steel,
| but I absolutely do care if I order a pizza and they just
| dump a load of gravel onto my plate and tell me it's good
| enough, and after all, quality isn't the point.
| dragonwriter wrote:
| > Quality absolutely matters, but it's hyper context
| dependent.
|
| There are very few software development contexts where the
| quality metric of "does the project build and run at all"
| doesn't matter quite a lot.
| falkensmaize wrote:
| Software that won't compile and doesn't do anything is not
| software, it's just a collection of text files. A computer
| that won't boot isn't a computer anymore, it's a
| paperweight. A car that won't start isn't a car anymore,
| it's scrap metal.
|
| I can bang on a keyboard for a week and produce tons of
| text files - but if they don't do anything useful, would
| you consider me a programmer?
| array_key_first wrote:
| Spending 24h/day to build nothing isn't impressive - it's
| really, really bad. That's worse than spending 8h/day to build
| nothing.
|
| If the piece of shit can't even compile, it's equivalent to 0
| lines of code.
|
| > Don't look at where the tech is. Look where it's going.
|
| Given that the people making the tech seem incapable of not
| lying, that doesn't give me hope for where it's going!
|
| Look, I think AI and LLMs in particular are important. But the
| people actively developing them do not give me any confidence.
| And, neither do comments like these. If I wanted to believe
| that all of this is in vain, I would just talk to people like
| you.
| ben_w wrote:
| > What they all seem to be just glossing over is how the
| project unfolded: without human intervention, using computers,
| in an exceptionally accelerated time frame, working 24hr/day.
|
| The reason I have yet to publish a book is not because I can't
| write words. I got to 120k words or so, but they never felt
| like the right words.
|
| Nobody's giving me (nor should they give me) a participation
| trophy for writing 120k words that don't form a satisfying
| novel.
|
| Same's true here. We all know that LLMs can write a huge
| quantity of code. Thing is, so does: yes
| 'printf("Hello World!");'
|
| The hard part, the entire reason to either be afraid for our
| careers _or_ thrilled we can switch to something more
| productive than being code monkeys for yet-another-CRUD-app
| (depending on how we feel), that 's the specific test that this
| experiment failed at.
| noosphr wrote:
| If this is what makes the AI bubble pop I'll laugh so hard.
| only-one1701 wrote:
| Wishful thinking. They're trying to (and maybe successfully)
| doing a military-industrial complex style thing with AI.
| noosphr wrote:
| Probably, but this is one of the few cases where instead of
| being told how amazing some AI tool is we are shown just what
| it can do.
| mikojan wrote:
| Dear god please let AI get forever stuck at this point because it
| would be so funny
| themafia wrote:
| Just view the "input cost" vs "output accuracy" graph.
|
| It _is_ stuck at this point.
|
| There's so much money involved no one wants to admit it out
| loud.
|
| They have no path to the necessary exponential gains and no one
| is actually working on it.
| bn-l wrote:
| The greatest grift of all time.
|
| I don't mean the tech itself---which is kind of useful. I
| mean the 99% of the value inflation of a kind of useful tool
| (if you know what you're doing).
| tyre wrote:
| AI is not a bigger grift than crypto. Crypto produced
| basically nothing of value. If all model improvement stops
| today, Opus 4.5 with Claude Code is a huge leap in
| productivity building certain types of software.
| mirsadm wrote:
| I would disagree on the huge boost to productivity but it
| is a very useful tool.
| Kiro wrote:
| Hilarious thing to say when we've just had some of the
| biggest leaps ever with Gemini 3 and Opus 4.5.
| lifetimerubyist wrote:
| Just one more new model bro the next one is AGI bro just give
| me a trillion dollars and I'll build the datacenters and
| everything will be perfect bro I promise bro please
| Kiro wrote:
| Even if it doesn't see any improvements beyond this point it
| wouldn't be a big deal. It's good enough for most programmers
| and any improvements are just a bonus.
| mikojan wrote:
| The masters of mankind are yearning to replace expensive tech
| workers with this. With agentic versions of LLMs we are at a
| point now where they can (and should) certainly try and
| create a more hilarious world
| ankit219 wrote:
| Like it or not, it's a fundraising strategy. They have followed
| it mutliple times (eg: vague posts about how much their inhouse
| model is writing code, online RL, and lines of code etc. earlier)
| and it was less vague before. They released a model and did not
| give us the exact benchmarks or even tell us the base model for
| the same. This is not to imply there is no substance behind it,
| but they are not as public about their findings as one would like
| them to be. Not a criticism, just an observation.
| alfalfasprout wrote:
| Unfortunately all the major LLM companies have realized the
| truth doesn't really matter anymore. We even saw this with the
| GPT-5 launch with obviously vibe coded + nebulous metrics.
|
| Diminishing returns are starting to really set in and companies
| are desperate for any illusion to the contrary.
| themafia wrote:
| I don't like it. It's lying in order to capture more market
| value than they're entitled to. The ends do not justify the
| means. This is a criticism.
| emp17344 wrote:
| Basically, fraud. Low-level fraud, but still fraud.
| csomar wrote:
| Low-level fraud? It's used to raise billions that could
| have been used for other purposes.
| nerdponx wrote:
| Fraud is just marketing in the 2020s now.
| skciva wrote:
| I'm not a fan of this either but I fail to see how its
| much different than the happy path tech demos of old.
| drawfloat wrote:
| The happy path was functional.
| horsawlarway wrote:
| Mmm, as someone forced to write a lot of last minute
| demos for a startup right out of school that ended up
| raising ~100MM, there's a fair bit of wiggle room in
| "Functional".
|
| Not that I would excuse Cursor if they're fudging this
| either - My opinion is that a large part of the growing
| skepticism and general disillusionment that permeates
| among engineers in the industry (ex - the jokes about
| exiting tech to be a farmer or carpenter, or things like
| https://imgur.com/6wbgy2L) comes from seeing first hand
| that being misleading, abusive, or outright lying are
| often rewarded quite well, and it's not a particularly
| new phenomenon.
| drawfloat wrote:
| But this isn't wiggle room, it flat out doesn't compile
| or run.
| Jcampuzano2 wrote:
| Never releasing the benchmarks or being openly benched unlike
| literally every other model provider always irked me.
|
| I think they know they're on the backfoot at the moment. Cursor
| was hot news for a long time but now it seems terminal based
| agents are the hot commodity and I rarely see cursor mentioned.
| Sure they already have enterprise contracts signed but even at
| my company we're about to swap from a contract with cursor to
| Claude code because everyone wants to use that instead now -
| especially since it doesn't tie you to one editor.
|
| So I think they're really trying to get "something" out there
| that sticks and puts them in the limelight. Long
| context/sessions are one of the hot things especially with
| Ralph being the hot topic so this lines up with that.
|
| Also I know cursor has its own cli but I rarely see mention of
| it.
| PlatoIsADisease wrote:
| I used to hate this, I've seen Apple do it with claims of
| security and privacy, I've seen populist demagogues do this
| with every proposal they make. Now I realize this is just the
| reality of the world.
|
| Its just a reminder not to trust, instead verify. Its more
| expensive, but trust only leads to pain.
| callc wrote:
| "Lying is just the reality of the world" is a cop-out
|
| Don't give them, or anyone, a free pass for bad behavior.
| pessimizer wrote:
| The reality of the world is that nobody needs a pass from
| you.
| autoexec wrote:
| Fraud, lies, and corruption are so often the reality of the
| world right now because people keep getting away with it. The
| moment they're commonly and meaningfully held accountable for
| lying to the public we'll start seeing it happen less often.
| This isn't something that can't be improved, it just takes
| enough people willing to work together to do something about
| it.
| nerdponx wrote:
| Several major world powers right now are at the endgame of
| a decades-long campaign to return to a new Gilded Age and
| prevent it from ending any time soon. Destroying the
| public's belief in objective truth and fact is part of the
| plan. A side effect is that fraud in general becomes
| normalized. "We are cooked" as the kids say.
| autoexec wrote:
| Fraud is not a very innovative fundraising strategy, but sadly
| it does sometimes work
| ironbound wrote:
| Devin 2.0
| heliumtera wrote:
| Making it compile will considerably decrease productivity. PR
| number go up
| logicallee wrote:
| (this has been fixed)
| embedding-shape wrote:
| Thank you for telling me about the email, it had a typo :( Been
| fixed now.
|
| Regarding the downvotes, I think it's because it's feeling like
| you're pushing your project although it isn't really super
| relevant to the topic. The topic is specifically about Cursor
| failing to live up to their claims.
| jonathanstrange wrote:
| I think it's only a matter of time until this becomes reality.
| It's almost inevitable.
|
| My prediction last year was already that in the distant future -
| more than 10 years into the future - operating systems will
| create software on the fly. It will be a basic function of
| computers. However, there might remain a need for stable,
| deterministic software, the two human-machine interaction models
| can live together. There will be a need for software that does
| exactly what one wants in a dumb way and there will be a need for
| software that does complex things on the fly in an overall less
| reliable ad hoc way.
| falkensmaize wrote:
| We might cure cancer in 10 years. We could have Martian
| colonists in the next decade. Everyone might be commuting to
| work with a jet pack. Literally anything _could_ happen,
| especially given a long enough time horizon.
| jonathanstrange wrote:
| You do realize that AI can already today write fairly complex
| software autonomously, don't you? It's not as if I haven't
| tested that. It works quite well for certain tasks and with
| certain programming languages.
|
| Anyone who knows history knows that people initially tend to
| underestimate the impact of technologies, yet few people
| learn something from that lesson.
| ares623 wrote:
| Can't help but draw parallels to how working with AI feels like.
| Your coworker opens a giant impressive looking PR and marks it
| ready for review. Meanwhile it's up to someone else in the team
| to do the actual work of checking. Meanwhile the PR author gets
| patted on the back by management for being forward thinking and
| pro-active while everyone else is "nitpicky" and holding progress
| back.
| callc wrote:
| I'm dealing with similar issues.
|
| It's reasonable to come up with team rules like:
|
| - "if the reviewer finds more than 5 issues the PR shall be
| rejected immediately for the submitter to rework"
|
| - "if the reviewer needs to take more than 8 hours to
| thoroughly review the PR it must be rejected and sent back to
| split up into manageable change sets"
|
| Etc etc. let's not make externalizing work for others
| appropriate behavior.
| tyre wrote:
| Eight hours to review! Girlie how big are these PRs?
|
| I can't imagine saying, "ah, only six hours of heads down
| time to review this. That's reasonable."
|
| A combination of peer reviewed architecture documentation and
| incremental PRs should prevent anything taking nearly 8 hours
| of review.
| embedding-shape wrote:
| Agreed, if it takes 8 hours to review a PR, then the
| process is broken and you need to start talking before
| anyone starts writing code. I'd put the max window on maybe
| 30 minutes for a PR, otherwise we're doing something else,
| not a "last pass before merge into production".
| thewhitetulip wrote:
| Not to mention the fact that juniors can now put the entire
| problem statement in AI chatbot which spits out _some_ code.
| The said juniors then don't understand half the code and run
| the code and raise the PR. They don't get a pat on the back but
| this raises countless bugs later on. This is much worse as they
| don't develop skills on their own. They blindly copy from AI.
| LegitShady wrote:
| AI hype is just lying until you get caught
| jadenpeterson wrote:
| For my 11th or 12th birthday, I got a pet porcupine and I was
| ecstatic. It was my first pet, and I spent hours researching what
| they eat, what habitats they like, etc. I carefully curated my
| room to accommodate him (him being 'Sonic'), even keeping it
| clean for the first time in forever so I wouldn't lose him amidst
| the mess of soiled undergarments and such. He loved it, and I
| loved him. Of course, it made no difference when my uncle sat on
| him on Christmas morning. We rushed him to the vet, but they told
| us his scans showed fractures on several vertebrae or something
| like that. We took him home, and waited for him to die, but the
| waiting was too painful. I'll spare the details, but what
| transpired next involved my dad, his shovel, and a lot of tears.
|
| About an hour later, we got a call from the vet - they'd misread
| the scan, and Sonic was gonna be fine. I think I was traumatized
| at the time, but the whole thing later became an inside joke (?)
| for my family - "Don't kill your porcupine before the vet calls"
| (a la "Don't count your chickens before they hatch").
|
| I guess my point, as it pertains to Cursor, its AI offerings, and
| other corporations in the space is that we shouldn't jump the gun
| before a reasonable framework exists to evaluate such open-ended
| technologies. Of course Cursor reported this as a success, the
| incentive structure demands they do so. So remember - don't kill
| your porcupine before the vet calls.
| callc wrote:
| Welcome to HN, thanks for sharing. That's a very sad story, I
| hope you aren't traumatized still.
|
| A reasonable framework does exist. Since the claim is "we made
| a web browser from scratch" the framework is:
|
| 1. Does it actually f*** work?
|
| 2. Is it actually from scratch?
|
| It fails on both counts. Further, even when compiled
| successfully, as others have pointed out, it takes more than a
| minute to load some pages which is a fail for #1.
| Shaanie wrote:
| If it loads pages, then it clearly works. Nobody claims it's
| a practical, competitive browser.
| callc wrote:
| "I built a car from scratch"
|
| ...
|
| "Nobody said it has brakes."
|
| Taken at face value, everyone assumes when you say
| statement #1 that you are not speaking like a lawyer.
| thewhitetulip wrote:
| > other corporations in the space is that we shouldn't jump the
| gun before a reasonable framework exists to evaluate such open-
| ended technologies
|
| How else will they raise a Bajillion $ for the next model?
| mslate wrote:
| No one's killing a porcupine here.
| solid_fuel wrote:
| This is par for the course with this AI slop. Most of the big
| claims about LLM productivity have completely lacked any backing
| evidence. Big claims require big evidence, but all I've seen so
| far is loud assertions and pathetic results.
| callc wrote:
| I'm happy that this shows that hard work, understanding your
| codebase, having performant software, having actually working
| software, rigorously measuring and proving proof of results
| still matters.
|
| There's a huge difference between using LLMs to offload any
| hard work and for LLMs to be of some assistance while you are
| in control and take ownership of the output.
|
| Unfortunately, the general public probably didn't try a git
| clone and cargo build, and took the article at face value.
| sidgarimella wrote:
| there's a curve where something of a conservative middle in AI
| marketing stunts are held to a higher level of criticism than
| headlines on either side
| wilsonzlin wrote:
| Hey, Wilson here, author of the blog post and the engineer
| working on this project. I've been reading the responses here and
| appreciate the feedback. I've posted some follow up context on
| Twitter/X[0], which I'll also write here:
|
| The repo is a live incubator for the harness. We are actively
| researching the behavior of collaborative long running agents,
| and may in the future make the browser and other products this
| research produces more consumable by end users and developers,
| but it's not the goal for now. We made it public as we were
| excited by the early results and wanted to share; while far off
| from feature parity with the most popular production browsers
| today, we think it has made impressive progress in the last <1
| week of wall time.
|
| Given the interest in trying out the current state of the
| project, I've merged a more up-to-date snapshot of the system's
| progress that resolves issues with builds and CI. The
| experimental harness can occasionally leave the repo in an
| incomplete state but does converge, which was the case at the
| time of the post.
|
| I'm here to answer any further questions you have.
|
| [0] https://x.com/wilsonzlin/status/2012398625394221537?s=20
| eloisius wrote:
| That doesn't really address much of the criticism in this
| thread. No one is shocked that it's not as good as production
| web browsers. It's that it was billed as "from scratch" but
| upon deeper inspection it looks like it's just gluing together
| Servo and some other dependencies, so it's not really as
| impressive or interesting because the "agents" didn't really
| create a browser engine.
| M4v3R wrote:
| Upon deeper inspection? Someone checked the Cargo file and
| proclaimed it was just Servo and QuickJS glued together
| without actually bothering to look if these dependencies are
| even being used.
|
| In reality while project does indeed have Servo in its
| dependencies it only uses it for HTML tokenization, CSS
| selector matching and some low level structures. Javascript
| parsing and execution, DOM implementation & Layout engine was
| written from scratch with only one exception - Flexbox and
| Grid layouts are implemented using Taffy - a Rust layout
| library.
|
| So while "from scratch" is debatable it is still immensely
| impressive to be that AI was able to produce something that
| even just "kinda works" at this scale.
| acdha wrote:
| > So while "from scratch" is debatable it is still
| immensely impressive to be that AI was able to produce
| something that even just "kinda works" at this scale.
|
| "From scratch" is inarguably wrong given how much third-
| party code it depends on. There's a reasonable debate about
| how much original content there is but if I was a principal
| at a company whose valuation hinges on the ability to
| actually deliver "from scratch" for real, I would be
| worried about an investor suing for material
| misrepresentation of the product if they bought now and the
| value went down in the future.
| wilsonzlin wrote:
| Thanks for the feedback. I agree that for some parts that use
| dependencies, the agent could have implemented them itself.
| I've begun the process of removing many of these and
| developing them within the project alongside the browser. A
| reasonable goal for "from scratch" may be "if other major
| browsers use a dependency, it's fine to do so too". For
| example: OpenSSL, libpng, HarfBuzz, Skia.
|
| I'd push back on the idea that all the agents did was glue
| dependencies together -- the JS VM, DOM, CSS cascade,
| inline/block/table layouts, paint systems, text pipeline,
| chrome, and more are all being developed by agents as part of
| this project. There are real complex systems being engineered
| towards the goal of a browser engine, even if not fully there
| yet.
| RandyOrion wrote:
| Hi, there. Two questions about this repo [0].
|
| Can you show us what you did after people failed to compile
| that project [1]?
|
| There are also questions about the attribution of these commits
| [2]. Can you share some information?
|
| [0] https://github.com/wilsonzlin/fastrender [1]
| https://github.com/wilsonzlin/fastrender/issues/98 [2]
| https://gist.github.com/embedding-shapes/d09225180ea3236f180...
| realharo wrote:
| Make it port Firefox's engine to iOS, that's something people
| would actually use (in countries where Apple is forced to allow
| other browser engines).
| devmor wrote:
| I am just so utterly tired of AI companies lying about
| everything, constantly without end.
|
| The things that modern machine learning can do are absolutely
| incredible, mindblowing and have myriad uses. But this culture of
| startup scams to siphon money out of the economy and into the
| bank accounts of a few investment firms and a couple
| "visionaries" has just turned what should be an exciting field
| full of technical advancement into a deluge of mental sewage
| that's constantly pumped into our faces.
| DeathArrow wrote:
| So they prove that if you have enough money to burn you can use
| AI to generate terabytes of useless junk?
|
| Who would have thought of that?
| nubskr wrote:
| That's actually the state of autonomous coding in 2026, scale the
| output, skip the verification.
| thewhitetulip wrote:
| Also since firefox is FOSS and any model has reasonably been
| trained on the code base of at least Firefox if not also
| Chromium, it's not a shock that agents are able to generate a
| similar code!
| motbus3 wrote:
| If it just forks chromium because it found it on the web it would
| also claim it made a browser from scratch. LLM does not know. It
| is not a person, it is a thing, just an algorithm
| orourke wrote:
| I feel that getting anywhere into the neighborhood of "kind of
| working" for a project like this is noteworthy and a huge
| milestone. Maybe a better headline would be, however: Agents
| almost create a working browser.
| embedding-shape wrote:
| Yes, if Cursor claimed "We let autonomous agents run for weeks,
| and they produced millions of lines of code, and it kind of
| looks like a browser, and it kind of runs", then I wouldn't
| have written and published TFA.
|
| But their claim wasn't so nuanced, it was "hundreds of agents
| can work on a single codebase autonomously for weeks and build
| an entire browser from scratch that works (kinda)". Considering
| the hand-holding that seems to have been required to get it to
| compile, this claim doesn't seem to hold up to scrutiny.
| Snuggly73 wrote:
| I've watched them today work in the new repo -
| https://github.com/wilson-anysphere/fastrender/tree/main ,
| adding another 50k lines trying to optimize scroll/rendering
| performance (spoiler: not really)
|
| At this point, its 1.5mlocs without the vendored crates (so
| basically excluding the js engine etc). If you compare that
| to Servo/Ladybird which are 300k locs each and actually
| happen to work, agents do love slinging slop.
| elzbardico wrote:
| I think that the companies that have the mindset "Let's give
| engineers tools that can leverage their strengths and eliminate
| toil" have way more success than those scammy "get-rich-fast
| let's automate software development and stop paying those sv
| salaries, invest in us!!!" gigs like Cursor and Devin.
|
| Their whole attitude leads to them wasting time with those Willy
| the Coyote Plans instead of building good products like Amp.
| embedding-shape wrote:
| Huge distinction between the two, one is about "Augmenting the
| human intellect" and the other is about "Get rich quick", but
| unfortunately it seems it's hard even for software developers
| to see which is which sometimes.
| utopiah wrote:
| That's kind of hilarious (...ly sad) to read knowing that I have
| on my desk https://browser.engineering so I literally went the
| opposite direction some months ago.
|
| Not only did I actually build a Web browser myself, from scratch
| (ok OK of course with a working OS and Python, and its libraries
| ;) but mine, did work! And it took me what, few hours, maybe few
| days if adding it altogether but, not only it did work (namely I
| did browse my own Website with it) but I had fun with it (!), I
| learned quite a bit with it (including the provable fact that I
| can indeed build a Web browser, woohoo!) and finally I did it
| on... I want say few kilowatts at most, including my computer
| (obviously) but also myself and the food I ate along the way.
|
| So... to each their own \\_ (tsu)_/
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