>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 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 [0].
>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.
https://hacks.mozilla.org/2026/08/intent-to-ship-jpeg-xl/