Open source antispam projects
Every project in the registry tagged antispam, ranked by real GitHub adoption.
Privacy-first CAPTCHA alternative with proof-of-work
Next-Gen CAPTCHA and Spam Protection, GDPR compliant
Security framework that protects from within your product
Decentralized CAPTCHA for enhanced web security
Related tags
Frequently asked questions
How many open source antispam projects are there?
This registry tracks 4 projects tagged antispam, with 12,368 GitHub stars between them. The most-adopted is Cap at 7,798 stars.
Are these antispam projects free to use?
Yes — 3 of the 4 carry an explicit open-source licence across 3 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 antispam 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 antispam projects still maintained?
4 of the 4 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.