Defend Like Castles

mCaptcha is proof-of-work based captcha system that is privacy focused and fully automated.

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Libre software GitHub

Privacy focused

Doesn't track, doesn't profile your users.

Robust and Accurate

Got users behind NATs? No issues. We don't use IP address for rate-liming. NAT or not you get the mCaptcha experience.

Best-in-class UX

mCaptcha is silent, so silent that your users won't even feel it. No more annoying images, no more helping for Big Brothers with their ML stuff

Defend like castles

Our PoW-based solution defends fierily. mCaptcha makes attacking your site more expensive than what it will take for you to respond to the attacker's requests

Libre Software

Client libraries are licensed using proprietary-friendly free software licenses but the core is AGPL'd. We believe this is a tech that can change the way the web works so mCaptcha will always be free

xCaptcha drop-in replacement

Already using a captcha solution? No worries, our APIs are compatible with reCAPTCHA and hCaptcha!