SpamAnvil

SpamAnvil is a free, open-source WordPress anti-spam plugin and a genuine Akismet alternative. Instead of relying on static keyword lists, it uses large language models (LLMs) to understand comments in context and detect even sophisticated spam while approving legitimate comments.

It uses a defense-in-depth approach: a honeypot, a time trap, per-IP rate limiting and a heuristics engine block obvious bots for free before any AI call is made, so the AI is only spent on subtle cases. An optional "Open Mode" removes comment friction (no required name/email, login or moderation hold) while spam is removed automatically in the background.

SpamAnvil supports multiple AI providers including OpenAI, Anthropic Claude, Google Gemini, OpenRouter (including free models), Featherless.ai and any OpenAI-compatible API, so there is no cloud lock-in. It is privacy-first (IP addresses stored as salted keyed hashes, GDPR/LGPD compliant), stores API keys with AES-256-GCM encryption, and processes comments asynchronously via WP-Cron to keep sites fast. It is 100% free with no premium tier or subscription.