https://hacks.mozilla.org/2021/04/quic-and-http-3-support-now-in-firefox-nightly-and-beta/

[mdn-logo-m] Mozilla Hacks

[                    ]
Hacks on YouTube @mozhacks on Twitter Hacks RSS Feed Download Firefox

QUIC and HTTP/3 Support now in Firefox Nightly and Beta

[dragana_] By Dragana Damjanovic

Posted on April 16, 2021 in Featured Article, Firefox, and
Uncategorized

tl;dr: Support for QUIC and HTTP/3 is now enabled by default in
Firefox Nightly and Firefox Beta. We are planning to start rollout on
the release in Firefox Stable Release 88. HTTP/3 will be available by
default by the end of May.

What is HTTP/3?

HTTP/3 is a new version of HTTP (the protocol that powers the Web)
that is based on QUIC. HTTP/3 has three main performance improvements
over HTTP/2:

  * Because it is based on UDP it takes less time to connect;
  * It does not have head of line blocking, where delays in
    delivering packets cause an entire connection to be delayed; and
  * It is better able to detect and repair packet loss.

QUIC also provides connection migration and other features that
should improve performance and reliability. For more on QUIC, see
this excellent blog post from Cloudflare.

How to use it?

Firefox Nightly and Firefox Beta will automatically try to use HTTP/3
if offered by the Web server (for instance, Google or Facebook). Web
servers can indicate support by using the Alt-Svc response header or
by advertising HTTP/3 support with a HTTPS DNS record. Both the
client and server must support the same QUIC and HTTP/3 draft version
to connect with each other. For example, Firefox currently supports
drafts 27 to 32 of the specification, so the server must report
support of one of these versions (e.g., "h3-32") in Alt-Svc or HTTPS
record for Firefox to try to use QUIC and HTTP/3 with that server.
When visiting such a website, viewing the network request information
in Dev Tools should show the Alt-Svc header, and also indicate that
HTTP/3 was used.

If you encounter issues with these or other sites, please file a bug
in Bugzilla.

About Dragana Damjanovic

Dragana is the networking module owner of Firefox. She is responsible
for the Firefox's implementation of HTTP, HTTP/3, HTTP/2, WebSockets,
DNS, cache, etc.

  * @damjano_d

More articles by Dragana Damjanovic...

Discover great resources for web development

Sign up for the Mozilla Developer Newsletter:

E-mail [                              ]
[ ] I'm okay with Mozilla handling my info as explained in this
Privacy Policy.
Sign up now
Thanks! Please check your inbox to confirm your subscription.

If you haven't previously confirmed a subscription to a
Mozilla-related newsletter you may have to do so. Please check your
inbox or your spam filter for an email from us.

---------------------------------------------------------------------

No comments yet

Post Your Comment

Cancel Reply

Your name * [                         ]
Your e-mail * [                         ]
Spam robots, please fill in this field. Humans should leave it blank.
[    ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
             [                                                  ]
Your comment [                                                  ]
Submit Comment

[                                             ]
[                                             ]
[                                             ]
[                                             ]
[                                             ]
[                                             ]
[                                             ]
[                                             ]
Except where otherwise noted, content on this site is licensed under
the Creative Commons Attribution Share-Alike License v3.0 or any
later version.

the Mozilla dino logo