Lightweight, modern open-source CAPTCHA alternative designed using SHA-256 proof-of-work and JS instrumentation
Cost / License
- Free
- Open Source
Application type
Platforms
- Self-Hosted
- Docker
Portugal
EU
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 nine 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
58 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 typeApplication types
Platforms
- Self-Hosted
- Go (Programming Language)
- Docker
Canada
26 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.
Czechia- EU
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.
Switzerland
+9
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
Privacy-first, self-hosted CAPTCHA for the modern web. No Google. No telemetry. No visual puzzles. Protect your software from bots without handing over your users' data to a third party.
Cost / License
- Free
- Open Source (Apache-2.0)
Application type
Platforms
- Online
- Self-Hosted
- Python
- Software as a Service (SaaS)
Mexico
India
