Mozilla has announced plans to enable JPEG XL decoding by default in Firefox 157 [1]. This move is part of the browser's efforts to improve image handling and provide better support for modern image formats. JPEG XL is a newer image format that offers several advantages over traditional formats like JPEG, including better compression and support for advanced features like animation and progressive rendering [2].
The decision to enable JPEG XL by default in Firefox 157 follows several versions of the browser with experimental support for the format [3]. Mozilla has been testing JPEG XL support in its Nightly builds and has now deemed it ready for stable release [4]. The move is also seen as a response to Google's announcement of its intent to ship JPEG XL in Blink, the engine that powers Chrome [5].
However, not everyone is convinced that JPEG XL is ready for prime time. Some have raised concerns about the format's performance, particularly when it comes to lossless compression [6]. According to one measurement, lossless JPEG XL decoding is 30x slower than lossless WebP decoding, which could have significant implications for battery life and user experience on laptops and phones [7].
Despite these concerns, Mozilla believes that JPEG XL is ready for widespread adoption and is committed to making it a default feature in Firefox 157. The browser is expected to ship with JPEG XL support enabled by default on all platforms in late September 2026 [8].
