Lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work.
Portugal
EU
Cap Captcha vs reCAPTCHA Comments
- Cap Captcha is Free and Open Source
- Cap Captcha is Customizable, Lightweight and Privacy focused
Open Source Self-Hosted reCAPTCHA Alternatives
reCAPTCHA is not available as a self-hosted solution but there are some alternatives for power users and business that want to host a solution on-premise. The best open source Self-Hosted alternative is Cap Captcha. If that doesn't suit you, our users have ranked more than 25 alternatives to reCAPTCHA and eight of them are open source and available as a self-hosted solution so hopefully you can find a suitable replacement. Other interesting open source Self-Hosted alternatives to reCAPTCHA are Anubis, ALTCHA, mosparo and mCaptcha.
Alternatives list
33 Cap Captcha alternatives
49 Anubis alternativesApplies sha256 proof-of-work challenges to incoming HTTP requests, targeting AI crawlers, bots that ignore robots.txt, and automated scrapers, protecting server resources and preventing unwanted search engine indexing for privacy-focused sites.
Cost / License
- Free Personal
- Open Source (MIT)
Application type
Platforms
- Self-Hosted
- Go (Programming Language)
- Docker
Anubis vs reCAPTCHA Comments
Jesus DeboussierI put this on my company page and now my colleagues think I'm into furries
- Anubis is Free Personal and Open Source
- Anubis is Lightweight and Security-focused
20 ALTCHA alternativesALTCHA is a privacy-first solution built to help developers and website owners stop bots, spam, and automated abuse — without making things harder for real users. It replaces traditional CAPTCHA systems with a smarter, quieter approach to verification and threat detection.
ALTCHA vs reCAPTCHA Comments
Jesus DeboussierIts proof of work only - this is a delay mechanism only so I don't know why its in the "stop bots" category?
- ALTCHA is Free and Open Source
- ALTCHA is Privacy focused, Security-focused and Lightweight
mosparo is the modern solution for protecting your online forms from spam. The protection method is quite simple: mosparo blocks spam using rules matching the form’s data. The detection method is comparable to an e-mail spam filter.
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mCaptcha vs reCAPTCHA Comments
BiepIt is Free and Open Source. Inspectable.
- mCaptcha is Free and Open Source
- mCaptcha is Privacy focused
conCaptcha is a self-hosted captcha which is faster, more user-friendly and more customizable than other captchas - available for PHP and ASP.NET websites. Users no longer have to read any annoying text images, solve difficult math equations or play any puzzle games.
Cost / License
- Free
- Open Source (MIT)
Platforms
- Self-Hosted
Cost / License
- Free
- Open Source
Platforms
- Self-Hosted
Cost / License
- Free
- Open Source
Platforms
- Online
- Self-Hosted
Canada
Czechia
Switzerland
India
I tried cap captcha on my site and the bots just kept on spamming me.