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Top Cybersecurity companies in San Francisco

Companies defending or attacking software, networks, and cloud infrastructure. Filtered to companies headquartered in San Francisco.

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

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

  1. 1
    Cloudflare· San Francisco, California, United States
    • Post-IPO debt
    • 6.9k employees
    • Founded 2009
  2. 2
    HackerOne· San Francisco, California, United States
    • Series unknown
    • 6.6k employees
    • Founded 2012
  3. 3
    Bugcrowd· San Francisco, California, United States
    • Debt
    • 3.6k employees
    • Founded 2012
  4. 4
    Armis· San Francisco, California, United States
    • Series unknown
    • 1.3k employees
    • Founded 2015
  5. 5
    Sysdig· San Francisco, California, United States
    • Series G
    • 644 employees
    • Founded 2013
  6. 6
    Cobalt· San Francisco, California, United States
    • Series B
    • 534 employees
    • Founded 2013
  7. 7
    Corelight· San Francisco, California, United States
    • Series E
    • 472 employees
    • Founded 2016
  8. 8
    Horizon3.ai· San Francisco, California, United States
    • Series unknown
    • 391 employees
    • Founded 2019
  9. 9
    Upwind Security· San Francisco, California, United States
    • Series B
    • 391 employees
    • Founded 2022
  10. 10
    Nozomi Networks· San Francisco, California, United States
    • Private equity
    • 383 employees
    • Founded 2013
  11. 11
    Picus Security· San Francisco, California, United States
    • Series C
    • 313 employees
    • Founded 2013
  12. 12
    Panther· San Francisco, California, United States
    • Series B
    • 293 employees
    • Founded 2018
  13. 13
    Sift· San Francisco, California, United States
    • Secondary
    • 291 employees
    • Founded 2011
  14. 14
    Riot· San Francisco, California, United States
    • Series B
    • 220 employees
    • Founded 2020
  15. 15
    Vehere· San Francisco, California, United States
    • Private equity
    • 219 employees
    • Founded 2006
  16. 16
    Wallarm: API Security Leader· San Francisco, California, United States
    • Series C
    • 193 employees
    • Founded 2016
  17. 17
    AppOmni· San Francisco Bay Area
    • Series C
    • 156 employees
    • Founded 2018
  18. 18
    Workstreet· San Francisco, California, United States
    • 125 employees
    • Founded 2023
  19. 19
    Skybox Security· San Francisco, California, United States
    • Private equity
    • 115 employees
    • Founded 2002
  20. 20
    Monarch· San Francisco, California, United States
    • 115 employees
    • Founded 2017
  21. 21
    RSAC· San Francisco, California, United States
    • 113 employees
    • Founded 1991
  22. 22
    Bastille· San Francisco, California, United States
    • Series C
    • 99 employees
    • Founded 2014
  23. 23
    Batuta· San Francisco, California, United States
    • Series A
    • 97 employees
    • Founded 2019
  24. 24
    Uno (acquired by Okta)· San Francisco, California, United States
    • Seed
    • 89 employees
    • Founded 2020
  25. 25
    Material Security· San Francisco, California, United States
    • Series C
    • 86 employees
    • Founded 2017

Find engineers at Cybersecurity companies in San Francisco

San Francisco has long been a hub for Cybersecurity, and the list above ranks the largest Cybersecurity companies headquartered there by current headcount, drawn from public LinkedIn and Crunchbase records. With 120 matching companies in our index, this is a good map of where the Cybersecurity talent in San Franciscolives — useful whether you’re recruiting, partnering, or sizing a market.

The biggest Cybersecurity 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 “Cybersecurity engineers in San Franciscohiring senior staff” or “founders of Cybersecurity 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 Cybersecurity 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 07:49:47 GMT

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