Firefox is enabling JPEG XL by default in version 157

JPEG XL is finally coming to Firefox out of the box.

Mozilla developer Timothy Nikkel announced an intent to turn on JPEG XL decoding by default on all platforms in Firefox 157. Firefox uses a Rust-based decoder called jxl-rs and will support both animation and progressive rendering—features Safari's implementation currently lacks.

Why it matters: Next-gen image formats only succeed when browsers actually support them. Safari shipped JPEG XL support in 2023, but Chrome still hides it behind a feature flag with no clear launch date. Firefox enabling it by default gives the format its biggest push in years and puts heavy pressure on Google to follow suit.

Know this: Decode performance remains a hot debate. Early benchmarks shared on the Mozilla mailing list showed lossless JPEG XL taking roughly 30× longer to decode than lossless WebP while offering only a 10% file size reduction. To help address CPU load, Mozilla is landing multi-threaded decoding patches that bring overall speed slightly ahead of Safari.

Your move, Chrome.