https://jpegxl.info/why-jxl.html

Illustration showing some of the key features of JPEG XL

JPEG XL

JPEG XL is a next-generation image format that brings many
advantages.

[jpg]

Legacy-friendly

Lossless JPEG recompression

Existing JPEG images can be converted to JPEG XL in a 100%
reversible, lossless way. The resulting JPEG XL files will be about
20% smaller and can be converted back to the bit-exact original JPEG
file.

[fidelity]

High-fidelity

Visually lossless compression

JPEG XL can reliably apply lossy compression in a way that avoids any
visible compression artifacts, preserving fidelity while reducing the
file sizes significantly compared to other image formats -- e.g. 60%
smaller than JPEG.

[rgb]

HDR and Wide gamut

Stunning color accuracy

Display technology is increasingly capable of reproducing rich colors
with a high dynamic range. JPEG XL is specifically designed for
high-precision colors, so your images can be preserved perfectly
without any compromises.

[fast]

Fast

Saving and loading without waiting

Nobody likes to look at progress bars. JPEG XL was designed to be
fast on the hardware of today. No special hardware is needed to save
or load JPEG XL images in the blink of an eye.

[delivery]

Web delivery

Progressive decode, minimal overhead

JPEG XL has several features specifically for web delivery. It has
sophisticated options for progressively rendering an image while it
is loading, improving the user experience dramatically, regardless of
network conditions. It has minimal header overhead and
state-of-the-art compression also at web quality.

[equal]

Lossless

High-precision, fast and compact

Unlike its predecessor JPEG, JPEG XL also supports lossless
compression. Pixels can be stored at high bit depths (up to 32-bit)
and images can be saved faster than PNG while being 35% smaller.

[scalpel]

Superior compression

Small files, high quality

At all the relevant fidelity targets, from web quality to lossless,
JPEG XL offers the best available compression. Compressing with
surgical precision, it is unmatched in terms of quality per byte.

[painter]

Authoring

Layers and extra channels

JPEG XL has several features aimed at image authoring workflows: it
supports layers and can store additional channels like selection
masks and spot colors. It also supports CMYK for use cases targeting
printing.

[future]

Future-proof

Anticipating the future

The JPEG XL format was designed to last at least as long as its
predecessor JPEG. It has no baked-in limitations regarding image
dimensions or color precision, in order to be ready for not just the
image technology of today, but also that of tomorrow. It can
represent new kinds of image information like depth maps and thermal
imaging, and has mechanisms to extend such functionality in the
future in a way that can be deployed gradually.

[royalty-fr]

Royalty-free

Free for everyone

Unlike some other modern formats, JPEG XL is not encumbered by
patents nor does it require proprietary software. The reference
software, libjxl, has a permissive open source license and is a
production-ready library that can be (and already has been)
integrated into a variety of image-related software.

Software support

New, but rapidly gaining traction

Since JPEG XL is a new format (standardized in 2022), software
support is still limited. However the format is rapidly gaining
traction, and it is already supported in the most popular image
software.

Adobe Camera Raw Serif Affinity 2 GIMP Krita darktable FFmpeg
ImageMagick

More information about JPEG XL can be found on the libjxl community
website and on the official JPEG XL website.