proof of work Archives

Discover the best free and open source CAPTCHA tools for privacy-friendly bot protection, including proof-of-work and self-hosted options.

mCaptcha is a privacy-respecting CAPTCHA system that uses proof-of-work and adaptive difficulty to protect websites without image puzzles.

Cap is a lightweight, self-hosted CAPTCHA alternative using proof-of-work and browser instrumentation.

ALTCHA is a self-hosted, privacy-focused CAPTCHA alternative using proof-of-work to protect websites from bots, spam and abuse.

Tag: proof of work