Captcha services ALTCHA logo

ALTCHA

Czech Republic
EuOpen Source

ALTCHA is an open-source, privacy-first CAPTCHA alternative that uses a proof-of-work mechanism.

ALTCHA is developed by BAU Software s.r.o., headquartered in Brno, Czech Republic, and is a wholly Czech-owned, EU-registered project. It provides a self-hostable, open-source CAPTCHA for protecting websites, APIs and online services.

ALTCHA uses a proof-of-work challenge that needs no cookies, fingerprints or trackers, can be fully self-hosted, and offers a managed Sentinel option for advanced bot protection. As an open-source, EU-based service, ALTCHA is a strong alternative to Google reCAPTCHA and hCaptcha for teams that want privacy and full control over their CAPTCHA.

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