# Intent to Ship: JPEG XL – Mozilla Hacks – the Web developer blog

- Link: https://mundosamuelsuiri.qzz.io/noticias/tecnologia/intent-to-ship-jpeg-xl-mozilla-hacks-the-web-developer-blog/104326/samuelsuiri/2026/08/26/
- Published: 2026-08-26T09:43:56-06:00
- Author: SamuelSuiri

Intent to Ship: JPEG XL By [Jake Archibald](https://hacks.mozilla.org/author/jarchibald/)
Posted on August 24, 2026 in [Uncategorized](https://hacks.mozilla.org/category/uncategorized/)

It isn’t often that new image formats land in browsers. In the early 2000s we had
JPEG, GIF, and PNG. The 2010s gave us WebP, which was a modest step up from JPEG.
But the 2020s have given us two new image formats that are a big step up from previous
formats: AVIF and JPEG XL. We shipped AVIF back in 2021, and today we posted [our intent to ship JPEG XL](https://groups.google.com/a/mozilla.org/g/dev-platform/c/3YMV4MS34KA?pli=1).
[Chrome are also intending to ship](https://groups.google.com/a/chromium.org/g/blink-dev/c/-gDojQbDPRI),
and given there’s already a partial implementation in Safari, the format will be
supported across browsers before the end of the year. Shipping JPEG XL securely 
We added experimental support for JPEG XL behind a flag back in 2021. But, at 100,000
lines of multithreaded C++, we were concerned about the attack surface this added
to Firefox. So, [we laid down a challenge](https://github.com/mozilla/standards-positions/pull/1064)
to the JPEG XL team at Google Research: Build a safe, performant, compact, and compatible
JPEG XL decoder in Rust, and we’ll ship it. That challenge was met; Google Research
built [jxl-rs](https://github.com/libjxl/jxl-rs), and it’s the core of our JPEG 
XL support in Firefox. We also pushed for [high quality integration tests as part of an Interop 2026 investigation area](https://github.com/web-platform-tests/interop-jpegxl),
and [they’re coming along nicely](https://wpt.fyi/results/jpegxl?label=master&label=experimental&aligned).
Progressive rendering Although Safari shipped JPEG XL in 2023, their implementation
lacked some key features of JPEG XL – our favourite is progressive rendering, which
is something we pushed for in the Rust implementation. Progressive rendering means
the image can render as it’s downloading. Although the full image is 135 kB, with
only a few kB downloaded the user can determine the subject of the image. [Try the above demo image](https://random-stuff.jakearchibald.com/apps/partial-img-decode/?demo=sleeping-fox-progressive.jxl&density=2)
in a browser that supports JPEG XL & progressive rendering, like [Firefox Nightly](https://www.firefox.com/en-GB/channel/desktop/#nightly)–
move the slider to see how the image displays with just a portion downloaded.

**JPEG XL vs AVIF** Browsers will now have two modern image formats for developers
to choose from. Which you choose depends on your use-case. **JPEG XL:** Excels at
lossless imagery, progressive rendering, and further compressing JPEGs without quality
loss. **AVIF:** Excels at web-quality photographic images, and images that have 
a mix of sharp edges and flat surfaces. For example: The image above is a 116 kB
AVIF with a quality score ([SSIMULACRA 2](https://github.com/cloudinary/ssimulacra2))
of 62.8, meaning medium-high quality. To get the same quality, the JPEG XL image
would be 134 kB. At a SSIMULACRA 2 score of 80 (very high quality), the AVIF is 
227 kB, and the JPEG XL is 264 kB. But at lossless, the AVIF is 1.76 MB, and the
JPEG XL is 1.45 MB. A lossless WebP is 1.55 MB. Another example is a screenshot 
of the Interop 2025 scores: At a SSIMULACRA 2 score of 78 (very high quality), the
AVIF is 11.6 kB, and the JPEG XL is 23.8 kB. But at lossless, the AVIF is 164 kB,
and the JPEG XL is 92 kB. A lossless WebP is 96 kB. Although AVIF tends to produce
smaller files at web-quality than JPEG XL, AVIF only has basic progressive rendering
support. So, for very large images, it may be worth taking the filesize hit with
JPEG XL. The key is to test with a representative set of images for your site, at
a quality that works best for your users, and remember to [optimise for high density.](https://jakearchibald.com/2021/serving-sharp-images-to-high-density-screens/)
About Jake Archibald

Source: _[Intent to Ship: JPEG XL – Mozilla Hacks – the Web developer blog](https://hacks.mozilla.org/2026/08/intent-to-ship-jpeg-xl/)_

### Comparte esto:

 * [  Facebook ](https://mundosamuelsuiri.qzz.io/noticias/tecnologia/intent-to-ship-jpeg-xl-mozilla-hacks-the-web-developer-blog/104326/samuelsuiri/2026/08/26/?share=facebook)
 * [  X ](https://mundosamuelsuiri.qzz.io/noticias/tecnologia/intent-to-ship-jpeg-xl-mozilla-hacks-the-web-developer-blog/104326/samuelsuiri/2026/08/26/?share=x)

### Me gusta esto:

Me gusta Cargando…