Mozilla's Nova UI Redesign Releases With Firefox 157, Download and Check Features

As expected, Mozilla has officially released Firefox 157, bringing its new Nova UI resdesign to the stable channel along with several changes to video playback and WebRTC. The release lands today for general public, but we downloaded it yesterday and checked what’s new about it. Here’s everything you can expect from the Firefox’s latest UI redesign.

Firefox 157 makes the browser look very different

If you are unaware, Nova UI had already appeared in earlier Firefox builds behind an experimental setting, but Firefox 157 turns it on by default. Mozilla describes the redesign as its biggest visual refresh in years, with a softer look across tabs, menus, popovers, address bars and sidebars.

The new design uses more rounded UI elements and adds pastel colors and tinting throughout the browser. Mozilla has also brought back Compact Mode, while reducing some of the visual clutter around the interface. The Nova changes are not limited to the main browser window either. Mozilla has been updating areas such as the add-ons manager and theme picker to match the new design. Firefox 157 also removes Amazon as a built-in search engine.

Image credit: Mozilla

The latest version also improves video playback and WebRTC

The update also brings several changes for people who spend a lot of time watching or making video calls. Firefox 157 improves HDR video playback and video and audio synchronization when playback speed is changed. More importantly, WebRTC video calls can now use hardware AV1 decoding, replacing software AV1 decoding in supported scenarios.

That should reduce the processing work required for AV1 video calls on compatible hardware. Firefox 157 also includes additional developer-facing changes, although Mozilla’s full stable release notes are still being finalized. The current Mozilla documents hints at WebGPU functionality and other platform changes alongside the broader update.

You can download Firefox 157 right away

The release is also notable because Firefox is now following Mozilla’s new two-week release schedule. Mozilla introduced the faster cadence with Firefox 155 in September, saying the goal is to get completed features and fixes to users sooner. Firefox 157 will officially be available for desktop users later today, but if you are willing to try the Nova UI now, download it from the Mozilla’s FTP page.

In other Firefox news, Mozilla is expanding its Smart Window with new AI-powered capabilities. The browser is getting agentic Tasks that can track prices and handle other actions, while Mistral AI models will also power parts of the Smart Window experience.