Cap is a fast, lightweight, and modern open-source CAPTCHA alternative based on SHA-256 proof-of-work (PoW). It’s 250x smaller than hCaptcha, privacy-focused, fully customizable, and easy to self-host. Cap helps prevent spam and abuse without tracking users, making it ideal for privacy-conscious developers. Built for speed and simplicity, Cap is perfect for modern web apps, forms, and APIs that need secure, lightweight human verification.
Cap is a lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work.
It's:
- ⚡️ 250x smaller than hCaptcha
- 🔒️ Private
- 🌈 Fully customizable
- 🤖 PoW-based
- 🌳 Fully FOSS
- 💨 Invisible
