exa

Exa builds web search infrastructure that gives AI applications access to information beyond their training data. Its Search API supports coding assistants retrieving documentation and public code, chat agents answering questions, and business tools finding companies and people. Developers can configure searches for fast retrieval or deeper research with structured outputs and citations. Websets handles complex queries that take minutes to assemble matching results. Exa also powers Firefox’s desktop Smart Window and iOS Quick Answers, supplying live-web information for cited answers.

Co-founders Will Bryk, the CEO, and Jeff Wang brought experience building AI products at Cresta and data infrastructure at Plaid, respectively. Exa’s engineering approach combines its own web crawling and indexing infrastructure with specialized transformer models that represent documents as embeddings for retrieval. It built a custom vector database to support high query volumes and variable computation per search, and fine-tuned embedding models specifically for code search.

In May 2026, the company reported more than 400,000 developers and 5,000 companies using Exa, including Cursor, Cognition and HubSpot. It also announced a $250 million Series C led by a16z at a $2.2 billion valuation. Sacra estimated Exa’s annualized revenue run rate reached $10 million in September 2025.