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 reCAPTCHA AlternativesTop Anti-Spam Tools and other similar apps like reCAPTCHA
The best open source alternative to reCAPTCHA is Cap Captcha. If that doesn't suit you, our users have ranked more than 25 alternatives to reCAPTCHA and ten of them is open source so hopefully you can find a suitable replacement. Other interesting open source alternatives to reCAPTCHA are Anubis, Procaptcha, ALTCHA and mosparo.
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
Prosopo Procaptcha redefines user verification with a unique approach that emphasizes privacy and security. It's a pioneering solution designed to offer an alternative to conventional CAPTCHA systems that often compromise user privacy.
Cost / License
- Freemium
- Open Source (Apache-2.0)
Application type
Platforms
- Online
- Software as a Service (SaaS)
- Wordpress
+3
Procaptcha vs reCAPTCHA Comments
Peter JepefIt works better, it costs less, it doesn't track your users, it has invisible challenges for humans stops bots. Need I say more?
- Procaptcha is Freemium and Open Source
- Procaptcha is Privacy 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
26 mosparo alternativesmosparo 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.
+9
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
United Kingdom
Czechia
Switzerland
India
I tried cap captcha on my site and the bots just kept on spamming me.