Firefox 157 Will Enable JPEG-XL Support by Default

Mozilla has announced plans to officially support the JPEG-XL image format in Firefox. Experimental support has already been available since Firefox 152, but the full launch is scheduled for Firefox 157, whose release is expected in late September.

In this version, JPEG-XL decoding will be enabled by default on all available platforms. It is already turned on in Firefox Nightly builds — this helps verify its reliability ahead of the stable debut. In Mozilla's assessment, the implementation is mature enough to ship in the stable branch.

The developers' move follows Google, which has already rolled out JPEG-XL in Chrome. The company is also developing jxl-rs — a JPEG-XL decoder written in Rust that, according to its developers, combines high performance with safety. On the same day, Google formally confirmed its intention to enable JPEG-XL decoding in the Blink engine by default for all users.

JPEG-XL vs. AVIF

On the Mozilla Hacks blog, the developers compared JPEG-XL with the rival AVIF format. According to them, JPEG-XL is especially good at handling lossless images, supports progressive rendering, and allows existing JPEG files to be compressed further without any loss of quality.

AVIF, for its part, performs better on web-quality photographic images, as well as on pictures that combine sharp edges with uniform fills. Although AVIF usually yields a smaller file size at web quality, its support for progressive rendering remains only basic. That is why, Mozilla notes, for very large images it may be worth accepting an increase in file size for the sake of JPEG-XL's advantages.

The details of Mozilla's plan are laid out in a Mozilla Hacks blog post and in a message on the relevant mailing list.

Source: Phoronix