Firefox 158 introduces JPEG XL support

Mozilla has released Firefox 158, which includes native support for the JPEG XL image format. This update marks a significant step for the browser, as JPEG XL offers improved compression and advanced features compared to traditional formats like JPEG, PNG, and WebP.

JPEG XL features and benefits

JPEG XL supports a wider color gamut, HDR, and high bit depth, while also allowing for lossless encoding, animation, and alpha channels. It can compress images more efficiently, offering better quality at smaller file sizes or maintaining detail while reducing file size by up to 50% compared to standard JPEG.

Enhanced Smart Window functionality

Firefox 158 improves its "Smart Window" feature, which uses AI to assist users in browsing. The update allows the AI to automatically fill in form fields by extracting data from open tabs or stored auto-fill information, making the browsing experience more seamless and efficient.

Additional features and improvements

The update also includes support for translating text between Albanian, Belarusian, and Filipino languages. Other changes address visual issues with website icons on the Ubuntu theme and improve the accessibility of PDFs created from web pages by resolving rendering problems such as missing mathematical symbols.

Developer-focused updates

Firefox 158 introduces several features for web developers, including support for arithmetic with data types in the CSS calc() function, new options for notifications, and enhancements to WebAuthn user interfaces. These updates aim to improve the development experience and compatibility with modern web standards.

Availability of Firefox 158

Firefox 158 is available for download starting October 12, 2026, with updates for Windows, macOS, and Linux users beginning October 13. Linux repositories and app stores will follow later, and Ubuntu users will receive the update automatically through the Snap Store.

JPEG XL gains traction with Chrome

Google’s Chrome browser has also added native support for JPEG XL, joining Firefox and Safari in embracing the format. This move could accelerate the adoption of JPEG XL, which promises lighter file sizes and better image quality.

Industry context and future of JPEG XL

JPEG XL was developed by the Joint Photographic Experts Group and aims to replace older formats by offering better compression and features like HDR and transparency. While its adoption is growing, alternatives like AVIF and WebP remain relevant, ensuring the web continues to offer a range of image formats for users and developers.