Cardea – Proof-of-Work Comment Spam Protection for WordPress

Are you tired of anti-spam plugins that bloat your site, inject third-party tracking, or constantly upsell you on premium SaaS subscriptions? Are you looking for a straightforward, lightweight solution that just protects your comments without the extra baggage?

Then Cardea is the right tool for you.

Cardea is a radically simple, zero-dependency Proof-of-Work (PoW) comment spam protector. Developed transparently on GitHub as a purely open-source project, it does one thing and does it perfectly: it stops automated bot spam on native WordPress comments.

Why Choose Cardea? Cardea offers distinct advantages for site owners who value simplicity, privacy, and performance:

Hyper-Focused & Zero Bloat – Cardea is strictly dedicated to the native WordPress comment system. Unlike multi-purpose anti-spam plugins that inject heavy compatibility layers for various form builders and e-commerce platforms, Cardea remains extremely lightweight and performant—protecting only what you need protected.

100% Standalone & Sovereign – No external API keys. No commercial SaaS tiers. No phone-home telemetry. Cardea is entirely self-hosted and self-contained. Your comment protection never depends on a third-party service staying alive.

Strict Privacy (GDPR Compliant) – Because the Proof-of-Work computation happens locally in each visitor’s browser, there are no tracking cookies, no user profiles, and no third-party data transfers. Unlike cloud-based CAPTCHA solutions, Cardea transmits nothing to external servers—making it inherently GDPR-friendly.

Reduced Attack Surface – By doing one thing perfectly (protecting native comments), Cardea avoids the security vulnerabilities inherent in massive, multi-ecosystem integrations. A focused codebase means fewer CVEs and tighter security.

Plug-and-Play Simplicity – No complex routing rules. No integration toggles. No configuration mazes. Users simply activate Cardea and their discussion threads are protected immediately.