Exa is now powering search in Firefox
Firefox is bringing AI search to its browser, and Exa is the information layer behind it. Starting today, Exa powers Smart Window on Firefox desktop as well as Quick Answers on Firefox for iOS. This means that Firefox users will now get AI summaries in their browser, pulling from the live web rather than the LLM’s training data. Every answer includes cited sources in the response to build trust. The experience works around the world since answers come from Exa’s globally-sourced index of 1.4 trillion URLs and 100 billion documents.
Under the hood, Firefox calls Exa's /search endpoint to retrieve, rank, and extract the most relevant passages from each page, synthesizing a direct answer with inline citations. Smart Window on desktop uses this for open-ended web questions, and Quick Answers on iOS uses the same pipeline tuned for one-sentence answers on mobiles. Firefox can control the retrieval process, restricting to certain domains. e.g. "how do I use this browser?" answers from Mozilla's own support docs rather than a third-party blog. They can also control freshness for time-sensitive queries, and add filters for content moderation. Importantly for Firefox's privacy values, Exa retains none of Firefox's query data.
Firefox picked Exa after a thorough evaluation, including multilingual evals, latency profiling, and examination of safety and privacy handling. As Ajit Varma, Head of Firefox, puts it: "We aim to deliver users a different model, one where AI makes your browser empowering and helpful, with visible citations and with a zero-data-retention commitment. Without Exa, we couldn't build these great features."
It has been easy to partner with Firefox because of our shared values around openness, privacy, and trust. To learn more about those values, check out Will Bryk’s fireside chat with Ajit Varma, Head of Firefox.
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