What's new in Firefox 121.0?

Firefox 121.0 was released on December 19, 2023, bringing a number of new features and fixes to the popular web browser.

Firefox, whose Android version now supports 450+ extensions, now prompts Windows users to install the Microsoft AV1 Video Extension, which allows hardware decoding for the AV1 video codec. This feature can considerably enhance video playback performance. Firefox also enables macOS Voice Control commands, enabling users to control the browser using their voice.

Firefox on Linux now defaults to the Wayland compositor when available, which offers better support for touchpad and touchscreen gestures, swipe-to-nav functionality, per-monitor DPI settings, and improved graphics performance. Additionally, you can force links always to be underlined in the Firefox settings. Moreover, the PDF viewer has been improved by adding a floating button that simplifies the deletion of drawings, text, and images added to PDFs.

Finally, Firefox 121.0 supports several new web platform features, including the has() selector, hanging/each-line text-indent, balance text-wrap, lazy loading iframes, and tail call elimination in WebAssembly.

There are several other issues, which you can see here.

Overall, Firefox 121.0 is a significant update that brings several new features and improvements to the browser. If you’re a Firefox user, update to the latest version to take advantage of these changes.