Firefox Smart Window now runs on Mistral AI, and the beta has just crossed the Atlantic.
Mozilla announced the partnership with Paris-based Mistral on 16 September 2026.
At the same time, Smart Window opened to users in France, with full French-language support.
What is Firefox Smart Window?
Smart Window is a separate browsing mode in desktop Firefox, next to the Classic and Private windows. It adds a built-in AI assistant that can summarize a page, compare your open tabs and help you plan a task.
It can also find a page you visited last week from a rough description, and suggest tab groups. When it needs fresh facts, it searches the web through Mozilla's partner Exa and shows the sources.
You open it from the Firefox menu with New Smart Window. You need a Mozilla account, and the feature is still an early beta.
What Mistral brings
The model is Mistral Small 4, an open-weight model released in March 2026 under the Apache 2.0 license. Mozilla says it chose it largely for languages - it treats French and other languages as a core skill, not a layer on top of English.
Mistral is not the only option, though. The first time you open Smart Window, Firefox asks you to pick a model, and the list currently holds three:
- Gemini 3.1 Flash Lite (Google) - labeled Fast
- Qwen3-235B (Alibaba) - labeled Flexible
- Mistral Small 4 (Mistral AI) - labeled Personalized
Mistral takes the Personalized slot that OpenAI's gpt-oss-120B held earlier in the beta. Advanced users can also connect a custom model of their own.
Want to try Mistral outside the browser? Its own assistant app, Mistral Vibe, is free on Android.
Is it private?
Mozilla says Smart Window chats are saved on your computer, not on its servers. Mistral has agreed to keep no data from the requests it processes.
Not stored is not the same as never sent. Your question and the page it is about still travel to the AI provider to get an answer. Smart Window cannot see Private Windows, saved passwords or payment details.
Who can use it, and when
The beta runs in the US and Canada in English, and now in France in French. Mistral says the UK and Germany come next, later in 2026.
Everyone else can join the waitlist on Mozilla's Smart Window page. To be ready, grab the latest Mozilla Firefox for your desktop.
Not interested in AI? Turn it off
Firefox makes this easy. Open Settings, go to AI controls, and choose Blocked next to Smart Window.
To switch off every AI feature at once, use Block AI enhancements in the same section. About 1% of Firefox users have already turned that global switch on.
Want a Firefox-based browser with no AI in it at all? LibreWolf leaves it out along with telemetry, and Zen Browser offers a calmer take on the same engine.
Why this matters
Most AI browsers lean on one big US provider. Firefox is going the other way - a menu of models, with a European open-weight option among them.
If you are weighing up the new wave of AI browsers, our look at what to use now that ChatGPT Atlas is gone is a good next read.
Quick questions
Is Mistral the default model in Smart Window?
No. Firefox asks you to choose a model the first time, and you can change it later in AI controls or from the chat itself.
Does Smart Window work on Android or iPhone?
Not yet. It is desktop only for now.
Is Smart Window free?
Yes, the beta is free. You only need a Mozilla account.
The bottom line
Smart Window now gives you a European AI model to choose, and Firefox still lets you block AI completely. Tell us which side you are on.
Don't Open a .xmpeg File Before Reading This
3/5It's never a good sign when the potential malware you downloaded has the EXACT same filename as the example. ...
Read More →Free Popular IPTV Playlist: Where to Get Fres...
3/5How can you create a DSTV channels on IPTV?
Read More →How to Download HEVC Video Extension for Free
5/5Does anyone have the HEVC Video Extensions as an .exe file and can provide a download link?
Read More →