Mozilla is letting users opt into AI-enabled browser assistance. It has now been announced that Mistral will power Firefox Smart Window with Mistral Small 4. The French AI company will deploy to this browser in France and North America first, with the UK and Germany set to follow.
Conversations are not stored externally by default, Mistral notes in its announcement. Firefox Smart Window, still in beta, will make use of Mistral Small 4 at a modest 119 billion parameters. This is nowhere near small enough to run on local machines, but with just 6.5 billion activated parameters, the cost of inferencing will be reasonable. The AI assistant will help users with complex searches, find pages they can’t find anymore and pull info from open tabs.
Both companies highlight their open source credentials to bolster the move. Mozilla emphasizes that it has been building an open browser for over 20 years, while Mistral has released open-weight models since its first launch in 2023. Not every Mistral model is actually all that permissive, though, as models like Large 2 and Codestral carry restricted licences. In addition, it can’t be said that even Small 4, already half a year old, is all that impressive by current standards especially for the size. Cheap options like DeepSeek-V4.1 Flash are leagues ahead in intelligence benchmarks like those from Artificial Analysis, admittedly using five times as many parameters. The point is that the use case for the model here is modest, and that is just as well given the model’s limits.
Multilingual mastery
The two companies repeatedly note the importance of Mistral having fine-tuned on regional languages, dialects and cultural context. The idea is that responses feel native and thus not translated from an American default. Mistral says it is extending this capability to Firefox users worldwide.
Mozilla ruffled a fair few feathers when it first announced it would support AI at a deeply integrated level inside Firefox. Therefore, Smart Window is opt-in and, according to Mozilla’s own documentation, only uses tabs and history that users choose to share. Mozilla also works with the self-proclaimed privacy-respecting AI company Exa for current web retrieval and source display.
Support?
Support for AI-enabled features in consumer-facing products has been mixed as best. Open hostility is what often greets newfangled additions relying on the technology, especially in areas where companies have built a reputation against certain large players. Mozilla, in its position as the ever-present power behind Chrome’s major alternative, risks losing market share to privacy-conscious and AI-skeptical users who have plenty of options. Vivaldi in particular offers a pledge against ever integrating AI inside its browser. One of the company’s co-founders, Jon Stephenson von Tetzchner, has said the goal for Vivaldi is to “keep browsing human”.
Also read: Brave and Vivaldi remove Googles advertisement AI from their browsers