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Top AI companies in San Francisco

Companies building AI products, foundation models, and applied ML platforms. Filtered to companies headquartered in San Francisco.

Built from a search like: “Top AI companies in San Francisco”

Ranked by current headcount across AI companies headquartered in San Francisco. Refreshed daily.

  1. 1
    Genentech· South San Francisco, California, United States
    • Series A
    • 18.1k employees
    • Founded 1976
  2. 2
    OpenAI· San Francisco, California, United States
    • Series unknown
    • 7.8k employees
    • Founded 2015
  3. 3
    Liquid Trees· San Francisco, California, United States
    • Seed
    • 1.6k employees
    • Founded 2022
  4. 4
    Twist Bioscience· South San Francisco, California, United States
    • Post-IPO equity
    • 1.2k employees
    • Founded 2013
  5. 5
    WestEd· San Francisco, California, United States
    • Grant
    • 1.2k employees
    • Founded 1966
  6. 6
    Cytokinetics· South San Francisco, California, United States
    • Post-IPO debt
    • 729 employees
    • Founded 1998
  7. 7
    Invitae· San Francisco, California, United States
    • Post-IPO debt
    • 703 employees
    • Founded 2010
  8. 8
    Veracyte, Inc.· South San Francisco, California, United States
    • Post-IPO equity
    • 691 employees
    • Founded 2008
  9. 9
    Gladstone Institutes· San Francisco, California, United States
    • Grant
    • 582 employees
    • Founded 1979
  10. 10
    Denali Therapeutics· South San Francisco, California, United States
    • Post-IPO debt
    • 570 employees
    • Founded 2015
  11. 11
    Standard BioTools· South San Francisco, California, United States
    • Post-IPO equity
    • 521 employees
    • Founded 1999
  12. 12
    Vir Biotechnology, Inc.· San Francisco, California, United States
    • Post-IPO equity
    • 479 employees
    • Founded 2016
  13. 13
    Calico Life Sciences· South San Francisco, California, United States
    • 449 employees
    • Founded 2013
  14. 14
    AI Researcher· San Francisco, California, United States
    • 419 employees
  15. 15
    Modern Sales Pros· San Francisco, California, United States
    • 354 employees
    • Founded 2015
  16. 16
    The AI Collective· San Francisco, California, United States
    • 318 employees
    • Founded 2023
  17. 17
    Rigel Pharmaceuticals Inc.· South San Francisco, California, United States
    • Grant
    • 285 employees
    • Founded 1996
  18. 18
    FibroGen, Inc.· San Francisco, California, United States
    • Post-IPO debt
    • 274 employees
    • Founded 1993
  19. 19
    OPTIC· San Francisco, California, United States
    • Seed
    • 265 employees
    • Founded 2021
  20. 20
    Athena Alliance· San Francisco, California, United States
    • Seed
    • 248 employees
    • Founded 2021
  21. 21
    insitro· South San Francisco, California, United States
    • Series C
    • 247 employees
    • Founded 2018
  22. 22
    California Institute for Regenerative Medicine (CIRM)· South San Francisco, California, United States
    • 242 employees
    • Founded 2004
  23. 23
    Alumis· South San Francisco, California, United States
    • Post-IPO equity
    • 232 employees
    • Founded 2021
  24. 24
    IDEAYA Biosciences· South San Francisco, California, United States
    • Post-IPO equity
    • 232 employees
    • Founded 2015
  25. 25
    Lyell Immunopharma· South San Francisco, California, United States
    • Post-IPO equity
    • 222 employees
    • Founded 2018

Find engineers at AI companies in San Francisco

San Francisco has long been a hub for AI, and the list above ranks the largest AI companies headquartered there by current headcount, drawn from public LinkedIn and Crunchbase records. With 354 matching companies in our index, this is a good map of where the AI talent in San Franciscolives — useful whether you’re recruiting, partnering, or sizing a market.

The biggest AI companies in San Francisco tend to be the gravitational centres for specialised talent — senior engineers, ML researchers, applied scientists, designers — while the smaller ones compete on speed, equity, and proximity to founders.

Refolk converts this list into a live search. Ask for “AI engineers in San Franciscohiring senior staff” or “founders of AI companies in San Franciscowho left in the last 12 months” and Refolk returns a ranked shortlist with the evidence that earned each person a spot.

How this list is built

Refolk pulled AI companies headquartered in San Francisco from public LinkedIn and Crunchbase records, ranked them by current employee count, and kept those with at least 10 employees. The list refreshes once a day.

Last refreshed: Thu, 07 May 2026 07:45:17 GMT

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