Firefox now has a private AI assistant and it will not remember a thing you said

Key points

• Mozilla launched Firefox Smart Window (beta), an AI browsing assistant powered by Mistral's open-source models.
• Smart Window is live first for users in France and North America, with the UK and Germany expected to follow later in 2025.
• Conversations are not saved on Mozilla's servers by default, and Mistral has agreed to zero data retention.
• Mistral is fine-tuning its models on regional languages, dialects, and cultural context so responses feel locally relevant.
• Both companies describe the deal as an open-source alternative to AI assistants controlled by a single large technology platform.

Your browser already knows a lot about you. Every tab you opened, every link you almost clicked, every topic you half-researched before getting distracted. Mozilla wants to put an AI assistant inside Firefox that can help make sense of all of that without handing your data to a big tech company.

The tool is called Firefox Smart Window, currently in beta (an early version open to testers). It can summarise complex searches, remind you of things you clicked away from, and pull together information from your open tabs. It now runs on models built by Mistral AI, the French startup that publishes its artificial intelligence models as open-source software, meaning anyone can inspect or build on the underlying code.

What does "private" actually mean here?

Privacy here has a specific, concrete meaning: your chat history is not stored on Mozilla's servers by default. Mistral has also agreed to zero data retention, so the company keeps no copies of your conversations on its end either.

That's a genuine difference from how most AI assistants work. Many popular chatbots save conversation history to train future versions of themselves or serve targeted features. Firefox Smart Window, as described in Mistral's announcement, skips that by design.

Anthony Enzor-DeMeo, CEO of Mozilla Corporation, put the ambition plainly: "A browser shouldn't be a one-way funnel. It should preserve what made the internet powerful to begin with: the freedom to explore, discover different ideas, and decide for ourselves where to go next."

Will it understand your language and accent?

Yes, that is the explicit goal. Mistral is fine-tuning its models on regional languages and dialects so the assistant gives answers that feel locally natural rather than translated from a one-size-fits-all base.

The rollout reflects that. France and North America go first, with the UK and Germany following later in 2025. More regions are implied by the partnership's stated mission, though no further dates are confirmed.

Arthur Mensch, Mistral's CEO and co-founder, described the aim as "bringing privacy, control and choice to AI-powered web browsing." The open-source part matters practically: independent researchers can check what the model actually does, which isn't possible with closed proprietary systems. A Mozilla report we covered on 15 September found the gap between expensive closed AI and the best open models is already shrinking for everyday tasks, which makes a deal like this more credible than it would have been a year ago.

Should you switch browsers for this?

Probably not yet, but the question is worth asking. The real test isn't whether the privacy architecture is solid, it's whether ordinary people care enough to choose Firefox Smart Window over the AI assistant already baked into their default browser. Mozilla is betting they will, or at least that they should have the option. That bet is worth watching.