Firefox 157 to ship JPEG XL by default on all platforms
Firefox 157 will include JPEG XL by default on all platforms
Mozilla engineer Timothy Nikkel announced that Firefox 157 will enable JPEG XL decoding by default across all platforms. The decoder, jxl-rs, is written in Rust and has been developed behind a preference, with a Firefox Labs checkbox since version 152. The announcement highlights performance improvements, feature parity with other formats (including animation and progressive display), and extensive testing. However, a community member raised concerns about lossless JPEG XL being 30x slower to decode than lossless WebP, suggesting a possible trade-off.
I am concerned about lossless JPEG XL performance. In my measurements it is 30x slower to decode than lossless WebP, in exchange for a 10% reduction in file size.
- concinds
With both Firefox and Chromium using jxl-rs (Rust-based), I wonder what Apple will do about the libjxl (C++) they already shipped. I know they're doing some memory-safety with Swift, but are they shipping any Rust in their platforms so far? I also wonder if anyone's done benchmark comparisons between both libs.
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Also, I was under the impression that after backtracking, Chromium was relying on Mozilla to come up with a Rust port, but it seems it was the reverse. Good on Google Research.
https://hacks.mozilla.org/2026/08/intent-to-ship-jpeg-xl/
> So, we laid down a challenge 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, and it’s the core of our JPEG XL support in Firefox.
- Nition
I had assumed that JPEG XL was for JPEGs that are Xtra Large, since that's what XL means on clothing and pretty much everywhere else. But apparently not:
> 'The etymology of the name "XL" is as follows: JPEG has called all its new standards since j2k something that starts with an X: XR, XT, XS (S for speed, since it is very fast and ultra-low-latency), and now XL. The L is supposed to mean Long term, since the goal is to make something that can replace the legacy JPEG and last as long as it did.'[1]
- Gander5739
Chrome appears to be doing the same: https://groups.google.com/a/chromium.org/g/blink-dev/c/-gDoj...
- rdsubhas
JXL is one of the technologies that I hope we can fully transition over, i.e. in a couple of years nobody (even non-tech-savvy people) are sharing or copying or saving JPEGs.
- yboris
I'm curious how many HN people in 2026 have not yet heard of JPEG XL / jxl
- pxoe
Now I'd only wish browsers could come up with more convenient ways to get around when some websites and upload fields don't support jxl or some other image format, and would either do something about it automatically or offer some option to get around it (convert to jpeg or png and upload, or 'paste as an image' which would pretty much be the same as png conversion, or something)
- xacky
Will they add it to Firefox 115 for the remaining Windows 7/8 users or will you need a new operating system to add an image format?
- cubefox
More information on JPEG XL progressive decoding and file size comparisons with AVIF: