FIREFOX 158.0 has been released with a notable change: default support for the JPEG XL image format. The update enables JPEG XL by default, so Firefox now automatically requests image/jxl when a site advertises JPEG XL support, removing the previous need for users to enable the feature in experimental settings. JPEG XL is described as a royalty-free format supporting lossy and lossless compression, transparency, smooth animation, HDR capabilities, and the ability to convert legacy JPEGs.
When servers recognise JXL support, they should deliver the optimal format; sites that don’t support it can fall back to traditional formats such as JPEG, WebP, AVIF, or PNG. The piece notes that Google Chrome had already adopted default JPEG XL support, and that Firefox 158.0 aligning with that decision could accelerate adoption worldwide.
In addition to JPEG XL changes, Firefox 158.0 brings several other enhancements. It adds CSS typed arithmetic operations, enabling functions like calc() to perform division across same-typed values with different units and then convert the result to another data type.
The release also introduces the WebTransport[.]getStats() method for gathering session data and statistics, and it refines WebDriver automation, including more precise control over camera and microphone permissions and easier specification of maximum screenshot dimensions. The update is described as rolling out across desktop and mobile platforms, with users able to update via the built-in mechanism. The article presents these changes as part of a broader, progressive upgrade to a more capable, security-conscious browser.