Sublime Black alternatives
TL;DR: 12 companies doing similar work to Sublime Black in B2B, ranked by how closely they match what Sublime Black 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 Sublime Black. They are scored on how closely their own description overlaps with Sublime Black's, and all facts shown come from the YC company records — nothing is estimated.
What are the best alternatives to Sublime Black?
| Alternative | What it does | Batch | Team | Status |
|---|---|---|---|---|
| Cymmetria | Shifting the asymmetry of cyber security. | Summer 2015 | 11 | Acquired |
| ContraForce | Security Delivery Platform to orchestrate AI agents for Service… | Summer 2021 | 15 | Active |
| Kestrel AI | AI Agents for Platform Engineering | Fall 2025 | 2 | Active |
| Fithub | — | Winter 2010 | — | Inactive |
| Insoshi | — | Winter 2008 | — | Inactive |
| AmberBox Gunshot Detection | Detect Gunshots | Inform Law Enforcement | Empower First Responders | Winter 2016 | — | Active |
| Optery | Opt out software that removes your private info from the internet | Winter 2022 | 55 | Acquired |
| Telivy | Automate your cyber security risk assessments | Summer 2021 | 6 | Acquired |
| EdgeBit | Autofix your software dependencies | Winter 2023 | 5 | Acquired |
| Xeol | Close your outdated dependency attack vector | Summer 2023 | 3 | Acquired |
| Hunter2 | Hunter2 trains engineering teams in application security through… | Winter 2018 | — | Acquired |
| Salt Security | Protects organizations from getting breached through their APIs. | Winter 2016 | 200 | Active |
Is Sublime Black still active?
Sublime Black is no longer listed as active, so anyone still relying on it should plan a migration to one of the alternatives above.
How was this list put together?
Every company here is Y Combinator-backed and shares at least one category with Sublime Black. They are then ranked on how closely their own description overlaps with Sublime Black's, so the closest matches come first rather than whoever happens to share a tag.