Mozilla has released Firefox 158, the latest version of its open-source web browser, with native JPEG XL image support, improved PDF generation on Linux and macOS, smoother scrolling, and several usability improvements across desktop and Android.
The most notable addition is support for JPEG XL, a modern image format designed to deliver better compression than traditional formats such as JPEG, PNG, and WebP while maintaining high image quality.
Unlike conventional JPEG, JPEG XL supports lossy and lossless compression, transparency, animation, and HDR images, and can convert existing JPEG files without losing quality. With Firefox 158, JPEG XL support is available directly in the browser, so users can view images in this format without changing settings.
Another welcome improvement, particularly for Linux users, concerns PDF generation. Firefox now uses SkPDF when generating PDF documents for saving or printing on Linux and macOS. According to Mozilla, the change improves PDF accessibility and fixes several rendering issues.
Scrolling has also improved. Previously, Firefox rounded scroll positions to whole pixels, causing small inaccuracies when moving through webpages. Version 158 removes this limit, allowing more precise scrolling, especially on high-resolution displays or at different zoom levels.
On the customization side, Firefox’s New Tab page now keeps a collection of previously selected custom wallpapers under a new “Your images” section. Before, the browser only remembered the most recent custom image, forcing users to select an earlier wallpaper again to reuse it.
Mozilla has also improved form filling in Smart Window. When users click a form field or choose the Fill option, the browser can suggest relevant information gathered from open tabs and saved autofill data, reducing the need to copy information manually between pages.
However, Mozilla notes that this feature is being introduced through a progressive rollout, so it won’t necessarily be available to everyone immediately.
Moreover, Firefox for Android receives a UI customization option. Users can now position the tab bar at either the top or bottom of the screen, depending on their preference. The option is available under Settings > Customize.
Several smaller fixes are included as well. On Windows, menus like List All Tabs, Settings, and Unified Search now behave more consistently with High Contrast themes. Users creating custom Windows themes can control menu background and text colors through system settings.
Finally, Mozilla has fixed a developer tools issue in which the Network Monitor could miss WebSocket messages arriving immediately after a connection was established.
Firefox 158 binaries are available from Mozilla’s download servers. Windows and macOS users will get an over-the-air update in the next few days. Linux users should see Firefox 156 in their distro repositories soon, too.
