Today, October 13, 2026, Mozilla released Firefox 158, notably enabling JPEG-XL image format support by default. This follows several months of opt-in testing for the format. JPEG-XL is designed to offer "better compression than other image formats, including WebP, PNG and regular ol’ JPEG," as noted by OMG! Ubuntu. It also supports wider color gamut, High Dynamic Range (HDR), high bit-depth, animation, alpha channels, and both lossless and progressive encoding. Other updates in Firefox 158 include improved PDF handling, refreshed New Tab page functionality, and enhancements to form filling within the AI-powered Smart Window browsing mode.