Proof of Human alternatives
TL;DR: 12 companies doing similar work to Proof of Human in B2B, ranked by how closely they match what Proof of Human actually does — not just by category.
How this list was built: every company here is Y Combinator-backed and shares at least one category with Proof of Human. They are scored on how closely their own description overlaps with Proof of Human's, and all facts shown come from the YC company records — nothing is estimated.
What are the best alternatives to Proof of Human?
| Alternative | What it does | Batch | Team | Status |
|---|---|---|---|---|
| Fithub | — | Winter 2010 | — | Inactive |
| Insoshi | — | Winter 2008 | — | Inactive |
| Hiro | Agents that handle security work | Summer 2023 | 2 | Active |
| Dyneti Technologies | Reduce payment fraud | Winter 2019 | 3 | Active |
| PromptArmor | LLM Security and Compliance | Winter 2024 | — | Active |
| Unbound | Use AI tools without fear of data leakage | Summer 2024 | 7 | Active |
| Observa | Catch accidental database exposures before the bad guys | Winter 2021 | 1 | Inactive |
| Optilly/Installmonetizer | Fb ad optimization platform | Winter 2012 | 11 | Inactive |
| Palisade | AI that finds and fixes OS-level vulnerabilities across device fleets | Summer 2026 | 1 | Active |
| Brushes | iPad drawing software. | Summer 2010 | — | Inactive |
| Castle | Block bots & bad behavior | Winter 2016 | 20 | Active |
| Sphere Secure Workspace | — | Summer 2015 | 2 | Acquired |
Is Proof of Human still active?
Proof of Human is still operating, so switching is a choice rather than a forced migration. Compare on fit and price rather than urgency.
How was this list put together?
Every company here is Y Combinator-backed and shares at least one category with Proof of Human. They are then ranked on how closely their own description overlaps with Proof of Human's, so the closest matches come first rather than whoever happens to share a tag.