WHAT IS IT?
ALTCHA is an open-source CAPTCHA widget that replaces reCAPTCHA, hCaptcha or Turnstile with a proof-of-work mechanism. No visual puzzles, no cookies, no tracking: the browser solves a cryptographic challenge in the background while the user fills out the form. Shipped as a standard Web Component, it integrates anywhere.
WHY IS IT INTERESTING?
- Ultra-lightweight: 30 kB gzipped vs 85 kB for Turnstile, 250 kB for hCaptcha and 300 kB for reCAPTCHA. Near-zero load time
- Full compliance: GDPR, HIPAA, CCPA out of the box, no special configuration needed. No data ever leaves for third-party servers
- Native accessibility: WCAG 2.2 AA and European Accessibility Act 2025 compliant. Audio challenges, RTL support and 50+ built-in languages
- Multi-layered defense: Proof-of-work is the first line, but ALTCHA also offers Human Interaction Signature analysis, proxy detection, rate limiting and IP geo-fencing
- Wide integrations: Starters for React, Vue, Svelte, Angular, Flutter, React Native. Server libs in TypeScript, PHP, Go, Python, Java, Ruby, Elixir. CMS plugins for WordPress, Drupal, TYPO3
USE CASES
- Protect contact or signup forms without degrading user experience
- Secure a public API while staying GDPR-compliant with zero extra legal overhead
- Replace reCAPTCHA on European websites to meet EAA 2025 accessibility requirements
- Deploy a self-hosted anti-spam solution on private infrastructure (Docker, Kubernetes, AWS ECS)