Firefox version 157, released with the codename 'Nova', introduces a significant visual overhaul that borrows the extremely rounded corner design from Apple's macOS Tahoe operating system and applies it uniformly across the browser’s interface. This change affects tabs, menus, buttons, and other UI components, giving Firefox a noticeably softer, more rounded appearance compared to earlier versions. The update reflects Mozilla’s effort to modernize the browser’s look by adopting contemporary design trends from competing platforms.
This image illustrates the Firefox 157 Nova UI redesign featuring macOS-inspired rounded corners across tabs, menus, and buttons as described in the article.
Users who prefer the previous, less-rounded appearance can disable the Nova rounding through Firefox’s advanced settings. By entering about:config in the address bar, acknowledging any warning, searching for the preference browser.nova.enabled, and setting its value to false, the browser reverts to the pre‑157 corner style after a restart. For finer control, advanced users can create a Chrome folder inside their Firefox profile directory, add a userChrome.css file, and insert CSS such as { border-radius: 0px !important; } to force square corners, or adjust the pixel value (e.g., 4px‑6px) to approximate the older look while keeping the Nova framework active.
Despite the aesthetic intent, some users report that the increased roundness actually hinders usability, noting that the rounded tabs make it more difficult to quickly identify which tab is active and that the change does not necessarily improve visual appeal for everyone. The article also cautions that the about:config toggle may be removed in future releases, leaving the userChrome.css method as the only potential workaround, though its longevity is uncertain.