A
ALTCHA
Freemium
Bot Protection & CAPTCHA
Open-source self-hosted captcha using proof-of-work, no external calls or data sharing
replaces:reCAPTCHA·hCaptcha·Cloudflare Turnstile
Czechia
DPA EU data Open Self-host
C
CAPTCHA.eu
Paid
Bot Protection & CAPTCHA
Invisible captcha hosted in Austria with WACA accessibility certification and per-site quotas
replaces:reCAPTCHA·hCaptcha·Cloudflare Turnstile
Austria
DPA EU data
F
Friendly Captcha
Freemium
Bot Protection & CAPTCHA
Invisible proof-of-work captcha that blocks bots without cookies, puzzles or tracking
replaces:reCAPTCHA·hCaptcha·Cloudflare Turnstile
Germany
DPA EU data