https://github.com/altcha-org/altcha

GDPR, WCAG 2.2 AA, and EAA compliant, self-hosted CAPTCHA alternative with PoW mechanism and advanced anti-spam filter.

antispam captcha captcha-alternative ddos-mitigation ddos-protection hcaptcha proof-of-work recaptcha spam-api spam-detection spam-filtering spam-prevention spam-protection svelte wcag webcomponent

Last synced: 23 May 2026