mCaptcha is an open-source CAPTCHA service designed for self-hosting enabling organizations to implement bot protection without external dependencies. The service uses proof-of-work technology for captcha verification. mCaptcha maintains compatibility with reCAPTCHA and hCaptcha APIs. The platform is licensed under AGPL emphasizing open-source principles. mCaptcha emphasizes privacy and user autonomy in bot protection. The service can be deployed on-premise for complete control.