Mosparo

mosparo is a self-hosted spam filter built specifically for web forms. Instead of making users solve puzzles, identify traffic lights, or type distorted text, it checks form submissions in the background and blocks spam before it reaches your inbox. The interaction is a single checkbox confirming consent, nothing more.

It sits in the broader space of CAPTCHA and bot protection tools, but takes a different stance from most. Tools like Friendly Captcha or Private Captcha still present users with a visible challenge to complete. mosparo skips the challenge entirely and focuses on analyzing what was actually typed into the form.

Key capabilities:

• No user friction. No image grids, math problems, or symbol matching. Works with mouse, keyboard, and touch, and is fully compatible with screen readers.
• Privacy-first data handling. Only uses data entered into the form, plus IP address and user agent. No cookies, no third-party tracking, no external data collection.
• Automatic data protection. Form entries are stored encrypted; IP addresses are hashed. Everything is deleted automatically after 14 days.
• Customizable appearance. The mosparo checkbox widget can be styled to match any site's design.
• Self-hosted. Runs on standard web hosting. You control where the data lives.

Because it's self-hosted, there's no dependency on a third-party service that could change its pricing or terms. The MIT license means you can use it freely, modify it, or contribute back. It's maintained by a Swiss non-profit association, which keeps it independent from commercial interests.

It's a practical fit for developers and site owners who want spam protection that doesn't frustrate legitimate users or compromise visitor privacy.