A first look at Firefox's new Nova UI, with the return of compact mode, in Nightly channel

Mozilla has enabled the Nova interface by default in Firefox's Nightly channel, marking a substantial update for early adopters. This new look introduces a more cohesive experience across tabs, menus, panels, and other browser surfaces. Notable changes include softer tab shapes, warmer color palettes, and a redesigned set of icons. The Nova design was first previewed in May as an opt-in feature via an about:config flag. Since then, Mozilla made refinements before activating it as the standard for Nightly builds.

Following user feedback, the update brings back compact mode. This lets users reduce the vertical space taken up by the interface, addressing concerns over the default layout's expanded title and tab bar area. Alongside this, additional theme options give users more control over the browser's appearance.

While these improvements are prominent in the Nightly channel, Nova remains a work in progress. Mozilla is soliciting feedback on visual and functional issues to further refine the experience before wider release.