French AI company Mistral and Mozilla have announced a partnership to make Mistral Small 4 the AI backbone of Firefox Smart Window — the browser maker's AI assistant feature that proactively surfaces relevant content and synthesizes information across open tabs.
The integration is initially available to users in the US, Canada, and France, with the UK and Germany expected to follow later in 2026. It is currently in beta.
The partnership's most notable commitment is a strict zero-data-retention policy: conversations with Smart Window are never stored on Mozilla's servers by default, and Mistral has committed to retaining user data for zero days — meaning it is discarded immediately after processing. The privacy angle sets this apart from most other browser AI features, though questions remain about whether data transits non-EU servers during processing.
The deal comes at a pivotal moment for Mistral, which recently raised 3 billion euros in a Series D round at a valuation exceeding 21 billion euros. The company has also been expanding its role as a cloud infrastructure provider and opened its platform to third-party models in August. For Mozilla, pairing with a European AI provider reinforces its longstanding emphasis on open-source values and user privacy.
