Mozilla ships redesigned Firefox 157 with returned Compact Mode and AI controls

Firefox 157 rolls out the redesign

Mozilla has begun shipping a redesigned Firefox to all users on desktop and mobile with version 157, according to a company blog post published on 29 September that quickly reached the Hacker News front page. The new look had been available in the Nightly preview channel for several months, where Mozilla says feedback from testers shaped the final release.

What actually changed

The refresh covers the whole interface: colors, icons and themes have been reworked everywhere from the tabs and toolbars people use daily to the New Tab page and Private Browsing mode. Mozilla claims the visual rework comes at no cost to browser performance, though that is the vendor's own assessment.

The same design language now spans desktop and mobile, which Mozilla presents as a consistent base for building new features rather than a one-off reskin. The stated design goal was an interface that feels up to date without sliding into sameness, and friendly without being sloppy.

Several concrete additions ship with the update:

• Compact Mode returns after users asked for it while testing the design. It shrinks tabs and the toolbar to give more of the screen to page content, with an auto-compact option for smaller displays.
• A new theme picker makes it simpler to browse and apply themes and wallpapers.
• The New Tab page now supports pinned shortcuts, so heavily used sites stay where the user puts them.

AI and productivity set the backdrop

Mozilla presents the redesign as the visible half of a year of functional changes. According to the post, the past twelve months brought side-by-side viewing of two pages, a built-in VPN layer for extra privacy, tracker blocking that Mozilla says improves scrolling and load times, and controls that decide how AI behaves in the browser, including which AI features appear, which model is used and what context it may access.

The post also lists partnerships with Wrexham, NVIDIA and Mistral alongside privacy features and the Kit mascot as things the company now associates with the Firefox brand. The NVIDIA and Mistral names connect the browser to prominent AI-industry players on the hardware and model sides respectively, though the announcement does not specify what those collaborations deliver inside Firefox itself.

Still independent, still open source

Mozilla emphasizes that the browser remains independent and open source, with privacy protections built in and settings that let users shape how the software works, from toolbar height to AI behavior. The company frames the update as a renewal rather than a reinvention, and closes the post by inviting users who drifted away from Firefox to give the new version a try.

Why it matters

The browser market is being reshaped again, this time around AI features that rivals increasingly bundle and switch on by default. Mozilla's answer, as sketched in this launch, takes the opposite posture: AI stays present but optional, with the user choosing the model, the features and the context. Pairing that stance with a modern, cross-platform design is a bid to remain relevant as a mainstream alternative rather than a niche privacy product.

The unified design language is also a practical bet, since features built once can land consistently on desktop and mobile, which matters for a smaller organisation competing against the largest browser vendors. For lapsed users, the redesign is an explicit invitation to look again. Whether any of this moves Firefox's share of the market is the open question that a fresh coat of paint cannot answer on its own.