mosparo is a free, self-hosted, open-source CAPTCHA alternative that stops form spam using content analysis. See features, setup, and alternatives.
mosparo is an open-source, self-hosted alternative to CAPTCHA that protects web forms from spam by analyzing submitted content rather than forcing users through visual puzzles. Founded in 2021 and maintained by the Swiss non-profit mosparo Association, it is released under the MIT license with source code publicly available on GitHub.
Instead of relying on a third-party service like Google reCAPTCHA, mosparo runs entirely on infrastructure the site owner controls, evaluating form submissions using rule-based content scoring, a honeypot field, and submission-timing analysis.
mosparo scores submitted form content against configurable spam rules, similar to how an email spam filter works, while an invisible honeypot field and timing analysis catch automated bot submissions that never see the honeypot or that fill forms too quickly to be human.
Because there are no puzzles, distorted text, or image challenges, mosparo is fully accessible via screen readers, keyboard, mouse, or touch. It also avoids tracking cookies, encrypts stored form data, hashes IP addresses, and deletes data automatically after 14 days by default.
mosparo is completely free and open source under the MIT license. There is no hosted SaaS product or paid tier; site operators install and run mosparo on their own web hosting.
Because it must be self-hosted, the only real cost is the operator's own server or hosting infrastructure, making it effectively free for anyone already running a website with standard hosting.
Yes, mosparo is fully open source under the MIT license with no paid plans; it must be self-hosted on your own server.
It analyzes the actual content submitted through a form using configurable spam-scoring rules, plus a honeypot field and submission-timing checks to catch bots.
No, mosparo does not use tracking cookies and only processes the data a user enters into the form, their IP address, and user agent.
mosparo is maintained by the mosparo Association, a non-profit organization based in Switzerland, with development happening openly on GitHub.
Yes, since it has no visual puzzles or image challenges, it is fully compatible with screen readers and works with mouse, keyboard, or touch input.
mosparo offers official and community plugins for platforms including WordPress, alongside a general API for custom integrations.