GoKawiilMozilla to enable JPEG XL image decoding by default in Firefox 157
Mozilla announced it will turn on JPEG XL decoding by default across all Firefox platforms starting with version 157, using its Rust-based jxl-rs decoder. The feature has been available as an opt-in Labs setting since Firefox 152 and behind a hidden preference since earlier releases, and now gains multithreaded decoding to match performance with Safari's implementation.
GoKawiil's interpretation of the reporting above, not reported fact.
JPEG XL adoption has been slow and contentious among browser vendors, with Chrome still only offering it as an experimental flag despite using the same underlying library. Firefox becoming the second major browser to ship it by default could pressure Google to reconsider its stance and give the format broader traction for web publishers.
- Firefox 157 will enable JPEG XL decoding by default on all platforms using the Rust-based jxl-rs decoder.
- Performance concerns were addressed via multithreaded decoding, making Firefox competitive with Safari's C++ implementation.
- Firefox's JXL support includes animation and progressive rendering, features missing from Safari's implementation, though HDR is still displayed as SDR.
Programming Rust, 2nd Edition (O'Reilly book) — Firefox's new JPEG XL decoder, jxl-rs, is written in Rust — the same memory-safe language Mozilla created and now uses for its riskiest parsing code. This O'Reilly guide is a thorough deep dive into the language behind that decision, covering ownership, concurrency and systems-level performance. A great pickup if browser-grade multithreaded image decoding sounds like something you'd like to write yourself.
See Programming Rust, 2nd Edition (O'Reilly book) on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: groups.google.com, 2026-08-25
Published there as: “Firefox 157 will include JPEG XL by default on all platforms”
Read the original report → The summary and analysis above are GoKawiil's own, written from reporting by the source above. Facts and quotes belong to the original publisher.