Firefox Beta and Developer Edition
Release Notes

Add, edit, and delete comments to make your own notes in PDFs (summaries, questions, tasks, etc.). The comment sidebar helps you scan all your comments and quickly jump to them, which is handy for long or heavily marked-up PDFs.

Need a reminder of what tabs are in a group? Hover over the tab group name to get a preview of the tabs inside without opening it.

Copy Link to Highlight allows users to share arbitrary sections of a page with others by copying a link through the context menu with a given selection

Starting with Firefox 145, Nightly and Early-beta builds can now find previously visited pages using Semantic History Search, which lets users recall sites with natural-language and concept-based queries, all processed locally for privacy. (Learn more)

Firefox no longer supports 32-bit Linux systems. We recommend installing the 64-bit version for continued updates and support.

Horizontal tabs are now slightly more rounded to match the look of vertical tabs. Buttons and text inputs, including the address bar, have also been updated for consistency.

When no extensions are installed, clicking the Extensions button now shows a message highlighting how extensions can enhance your browsing, with links to the Firefox Add-ons store.

Support has been added for the Atomics.waitAsync proposal, which is a non-blocking, asynchronous version of Atomics.wait. This allow synchronization of threads based upon the value in a shared memory location, for more details please consult our MDN documentation.

Firefox now supports the new Integrity-Policy header for enforcing sub-resource integrity for scripts. Further implementation of this header is underway. Further implementation of this header is underway.

Added Matroska support for the most commonly used codecs: AVC, HEVC, VP8, VP9, AV1, AAC, Opus, and Vorbis.

The text-autospace property is now supported, allowing automatic spacing adjustments between characters from different scripts.