PigCache replaces WordPress’s default object cache with Redis (official drop-in pattern), using PhpRedis when available or the bundled Predis. Configure the connection with PIGCACHE_REDIS_* constants in wp-config.php.

Features:

Redis object cache drop-in (PhpRedis or bundled Predis)
SQL query cache (optional db.php drop-in) with per-table invalidation, so writing to one table does not discard results that never read it
Full-page HTML cache for anonymous visitors with tag-based selective invalidation on content changes
Fragment caching helpers backed by Redis
Tag-based selective invalidation — only affected pages are purged when a post, term, or comment changes

Every feature listed above is included and fully enabled. The plugin has no license check, no trial period and no usage limit, and it does not contact any external service.

The object cache drop-in is derived from Redis Object Cache (GPLv3, Till Krüss / Rhubarb Group).

External services

This plugin does not connect to any external service. All caching, invalidation and metrics happen on your own server and your own Redis instance.