Open source spam-protection projects
Every project in the registry tagged spam-protection, ranked by real GitHub adoption.
Privacy-first proof-of-work CAPTCHA without user friction
GDPR-compliant bot protection without user friction
Invisible bot protection that respects user privacy
Related tags
Frequently asked questions
How many open source spam-protection projects are there?
This registry tracks 3 projects tagged spam-protection, with 2,718 GitHub stars between them. The most-adopted is mCaptcha at 2,490 stars.
Are these spam-protection projects free to use?
Yes — 2 of the 3 carry an explicit open-source licence across 2 distinct licences, so there is no licence fee. Where a project also sells a hosted or enterprise version, the self-hosted path remains free.
Which spam-protection project should I choose?
The list above is ranked by GitHub stars, but stars measure attention rather than fit. Check three things on each card: the licence (permissive versus copyleft), the language it is written in, and the last-push date — a high-star project that has not been pushed in a year is a liability.
Are these spam-protection projects still maintained?
2 of the 3 were pushed in the last 90 days, and every card shows its exact last-push date so you can see the rest. Sort your shortlist by that date before committing to a migration.