Firefox 157 Redesign Targets Chrome With Choice, AI Controls and Gecko
Firefox 157 brings a desktop and mobile redesign as Mozilla targets Chrome users with customization, AI controls, enterprise tools and wider Gecko adoption.
Summary
On September 29, 2026, Mozilla began rolling out Firefox 157 across desktop and mobile, modernizing the interface, restoring compact mode, and expanding customization to make the browser competitive on experience, not only privacy and open web values. Firefox chief Ajit Varma is targeting a mass audience choosing among Chrome, Microsoft Edge, and Safari. Firefox’s open source Gecko engine remains a principal alternative to Chromium while Google led Chromium dominates browsers. Forrester analyst Paddy Harrington calls Firefox’s biggest adoption barrier simply that it is not Chrome. Safari and Edge are bundled, yet users still install Chrome. Mozilla also gets most revenue from making Google Firefox’s default search engine, tying its independence to its largest rival.
Varma says EU Digital Markets Act mobile choice screens have increased Firefox adoption, while Chrome’s Manifest V2 shutdown triggered a user surge because Firefox retained the more powerful extension system. Top level AI controls can disable all prompts or select translation, summarization, tab grouping, and form filling, with Mozilla favoring on device and open source models rather than building its own. Varma contrasts this choice with Copilot in Edge and Gemini in Chrome, while citing ChatGPT and Claude as more widely used. AI work uses less than 10 percent of engineering, while 90 percent of attention remains on Gecko’s performance, compatibility, and developer APIs. Over the past 12 months, Mozilla’s biggest new investment has targeted enterprise and school manageability, data loss prevention, and digital sovereignty, particularly in Europe and Asia. A global Gecko iPhone release remains uneconomic because Apple’s EU and Japan exceptions require regional builds that could double the iOS team. AI coding has accelerated output, but code review is now the bottleneck. Google’s search strength persists despite LLMs, leaving diversification unresolved.
Positives
- Firefox 157 modernizes desktop and mobile interfaces, restores compact mode, and expands customization to appeal beyond privacy and open web advocates.
- EU Digital Markets Act choice screens have increased Firefox adoption by prompting mobile users to make an active browser selection.
- Firefox retained Manifest V2 support and gained users after Chrome disabled the more powerful extension system.
- Less than 10 percent of engineering targets AI, while 90 percent of attention remains focused on Gecko fundamentals.
- Mozilla’s biggest new 12 month investment adds enterprise and school controls, data loss prevention, manageability, and digital sovereignty capabilities.
Risks & concerns
- Chrome’s entrenched position remains Firefox’s biggest adoption barrier, even though Safari and Microsoft Edge are bundled with leading operating systems.
- Google provides most of Mozilla’s revenue through Firefox’s default search deal, financially linking the browser to its dominant competitor.
- Apple’s regional engine rules could force Mozilla to double its iOS team to maintain separate Gecko and non Gecko builds.
- AI assisted development has shifted Mozilla’s engineering bottleneck from producing code to reviewing it.
- Enterprise expansion will require Firefox to impress IT decision makers already committed to larger platform providers such as Microsoft and Google.