Self-hosted CAPTCHA & Bot Protection Tools
A curated collection of the best self-hosted tools for distinguishing humans from bots (CAPTCHA) and preventing spam.
Privacy-first CAPTCHA alternative with proof-of-work
Stars
7,937Last commit
2 days agoLicense
Apache-2.0
Lightweight open-source CAPTCHA solution using SHA-256 proof-of-work. 250x smaller than hCaptcha, fully customizable, and privacy-focused with zero telemetry.
Open Source Alternative to:
Next-Gen CAPTCHA and Spam Protection, GDPR compliant
Stars
2,800Last commit
1 day agoLicense
MIT
ALTCHA offers cutting-edge spam and abuse protection for websites and apps, with privacy-friendly CAPTCHA alternatives designed for GDPR compliance.
Open Source Alternative to:
Privacy-first proof-of-work CAPTCHA without user friction
Stars
2,492Last commit
1 year agoLicense
AGPL-3.0
Privacy-focused proof-of-work CAPTCHA system that silently protects websites without tracking users or requiring image solving. Drop-in replacement for reCAPTCHA.
Open Source Alternative to:
GDPR-compliant bot protection without user friction
Stars
195Last commit
12 minutes agoLicense
Unknown
Privacy-first CAPTCHA service that blocks bots while keeping forms accessible. No puzzles, no tracking, no cookies - just invisible cryptographic protection.
Open Source Alternative to:
Access control for AI agents your customers log in with
Stars
25Last commit
1 day agoLicense
BUSL-1.1
Detects AI agents using customer credentials, masks private fields, holds risky actions for passkey approval, and signs every decision on your own server.
Open Source Alternative to:
Docmost – Open-source wiki software with real-time collaboration, diagrams, AI, SSO, RBAC permissions and more.
Docmost