Mozilla launches Firefox 157 with a new Nova interface, practical improvements like compact mode, hardware-accelerated video calls, and critical security fixes, marking a significant update for users and enterprise controls alike.
Mozilla has released Firefox 157, and the most visible change is Nova, the browser’s redesigned interface. The update gives tabs, toolbars, menus, icons and the sidebar a cleaner, more modern look, while also revising the built-in light and dark themes. According to Mozilla’s release notes, the aim is to make the browser frame feel more coherent across the main window, panels and side features.
The redesign is not limited to cosmetics. Mozilla has changed the spacing and proportions of the interface so that the sidebar sits more naturally alongside vertical tabs, which are now more closely integrated into the rest of the browser chrome. The company says most themes should continue to work, although Mozilla’s add-ons team has warned that some themes, especially those built around background images, may appear differently because the browser frame and toolbar areas have been reworked.
A practical addition is the return of compact mode. Mozilla says this setting is intended to reduce the amount of vertical space taken up by the tab strip and toolbar, leaving more room for web content. It is most useful on smaller displays, such as laptops, and in split-screen setups where every line of screen space matters. For many users, that makes it easier to keep two documents, pages or windows open side by side without losing as much content to browser controls.
Firefox 157 also brings a useful technical improvement for video calls. On devices that support it, WebRTC calls can now use hardware decoding for AV1 video streams. Phoronix reported that this shifts part of the workload away from the CPU and onto dedicated video hardware, which can lower processor usage during calls and may help with battery life on portable machines. Mozilla has also fixed a bug that could cause video from some phones and tablets to appear rotated or upside down, and it has improved audio-video synchronisation when playback speed is changed repeatedly.
Security remains a major part of the update. Mozilla’s advisory for Firefox 157 lists multiple high-severity issues, including memory-safety flaws and sandbox-related vulnerabilities, and recommends updating promptly. The company has also changed how it publishes some memory bugs, separating issues that were previously grouped together, so the number of listed CVEs is not directly comparable with earlier releases. For everyday users, the key point is straightforward: this is not only a design refresh, but also an important security update.
There are a few smaller changes that matter in day-to-day use. Amazon has been removed from the default search engine list, although it can still be added manually. Keyboard navigation in the address bar has also changed, with Tab now moving directly to the text field rather than stopping first on the search engine button. Mozilla has additionally expanded enterprise controls, adding a SpeechRecognition option to its AIControls policy so administrators can permit or block on-device voice recognition, and it says the Nova redesign has been developed with a stronger focus on accessibility, including contrast, focus visibility and clickable target size.
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