Firefox has received a major design overhaul across desktop and mobile versions, featuring bubble-like tabs, a rounded address bar, and refreshed colours, icons, and themes. This modernisation aims to unify the desktop and mobile experience whilst maintaining performance, following a year of significant updates including home page widgets, Split View, and built-in VPN features.

The redesign introduces customisation options including a dozen colour themes (each available in light and dark modes) and additional wallpapers. Firefox 157 also reintroduces Compact Mode, a user-requested feature that reduces tab and toolbar sizes to maximise screen space for web content, with an auto-compact option for smaller devices. The rounded UI elements now give Firefox a visual similarity to Chrome, whilst Mozilla continues developing AI features like Smart Window AI mode to remain competitive.