Mozilla has released Firefox 157 with a broad interface refresh across desktop and mobile, plus the return of a space-saving feature that longtime users have been asking for. The update began rolling out on September 29, 2026, and is available as a free browser update.
The visible changes are meant to make Firefox feel more consistent without discarding its familiar structure. Mozilla has updated colors, icons, themes, menus and other controls, while adding more ways to tune how much room the browser occupies on screen. The company describes the redesign as a shared visual system for desktop and mobile rather than a one-platform makeover.
Compact Mode is back
The most practical addition is the return of Compact Mode. It reduces the height of the tab strip and toolbar, leaving more room for webpages. That can be useful on smaller laptops, split-screen setups and desktops where users keep many browser windows open.
Firefox 157 also includes an automatic compact option designed to switch to the denser layout when screen space becomes limited. Mozilla says the mode achieves the smaller footprint without a performance penalty. That is a manufacturer claim rather than a result of independent testing, but the feature itself is available in the released browser.
A cleaner look with more personalization
Mozilla’s official redesign announcement shows rounded interface elements, refreshed iconography and a clearer separation between browser controls and page content. A new theme picker makes light and dark themes easier to find, while the new-tab page can use wallpapers and configurable shortcuts.
The goal appears to be flexibility rather than a single fixed appearance. Users can keep a roomy layout, choose the denser Compact Mode or adjust the new-tab page to emphasize frequently used destinations. The design is recognizable as Firefox, so the update should not require people to relearn basic navigation.
Firefox 157 also changes more than the surface
The Firefox 157 release notes list several technical changes alongside the redesign. Hardware-accelerated AV1 decoding is now available for WebRTC, which can reduce the processing burden of compatible video calls. Firefox also adds a visible warning when TLS encryption-key recording is enabled, helping users notice a diagnostic setting that could expose sensitive session data if left on unintentionally.
Mozilla says it fixed an upside-down WebRTC video problem, an HDR display issue, audio-and-video synchronization trouble, a vertical-tabs sidebar problem and a Windows taskbar issue related to full-screen playback. As always, real-world impact will depend on a person’s hardware, operating system and the sites or services they use.
There are behavior changes worth noting too. Pressing Tab after clicking a link now moves focus forward from that link instead of restarting from the top of the page. Amazon has been removed as a built-in search provider. Firefox Suggest is expanding to additional European countries, so the exact suggestions a user sees may vary by region.
The sidebar transition still has an escape hatch
Firefox’s newer sidebar is now the default across the browser. People who rely on the previous sidebar can temporarily restore it through the advanced about:config setting sidebar.revamp. Mozilla says that fallback is planned to remain available through the end of 2027, giving users and extension developers more time to adjust.
That option is useful, but changing advanced preferences can affect browser behavior and should be done carefully. Most users are better served by trying the new sidebar first and changing the setting only if a specific workflow is disrupted.
Who should update?
For people already using Firefox, version 157 is a straightforward update: it costs nothing, adds security fixes and introduces practical layout choices without requiring a new account or subscription. Compact Mode is the clearest benefit for anyone working on a smaller display, while the refreshed themes and shortcuts may appeal to users who want the browser to feel less visually dated.
Anyone considering Firefox as an alternative to Chrome, Edge or Safari now gets a more polished first impression, but this release does not fundamentally change website compatibility or guarantee faster browsing. Mozilla’s larger pitch remains the same: an open-source browser with privacy controls and user choice at the center. The Verge’s launch report independently confirms the public release and the return of Compact Mode.
What remains uncertain
Mozilla has not published a quantified performance comparison for the redesigned interface, and we have not independently tested memory use, battery life or page speed in Firefox 157. Some features, particularly Firefox Suggest, are region-dependent. Interface updates can also expose extension-specific quirks that may not appear in the general release notes.
Still, this is a meaningful browser update because it combines visible improvements with fixes that affect video calls, displays and full-screen media. The return of Compact Mode is especially welcome: it gives users more screen space without forcing everyone into the same dense layout.
Featured image: Mozilla.