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wp cache type

Overview

Identify whether WordPress is using the default non-persistent in-memory cache or a persistent backend (Redis, Memcached). Essential first step for cache debugging and server configuration audits.

What It Does​

wp cache type reads the $_wp_using_ext_object_cache global and outputs the name of the active cache implementation class.

Syntax​

wp cache type

Basic Usage​

wp cache type

Output without persistent cache:

Default

Output with Redis Object Cache plugin:

WP_Object_Cache (Redis)

Output with Memcached:

WP_Object_Cache (Memcached)

Real-World Scenarios​

Scenario 1: Verify cache is installed after Redis setup​

# After installing Redis and the plugin
wp plugin install redis-cache --activate
wp redis enable

wp cache type
# Expected: WP_Object_Cache (Redis)

Scenario 2: Audit cache configuration on multiple sites​

for path in /var/www/site1 /var/www/site2 /var/www/site3; do
  TYPE=$(wp cache type --path="$path" 2>/dev/null)
  echo "$path: $TYPE"
done

Output:

/var/www/site1: Default
/var/www/site2: WP_Object_Cache (Redis)
/var/www/site3: WP_Object_Cache (Redis)

Scenario 3: Conditional flush based on cache type​

TYPE=$(wp cache type)
if [[ "$TYPE" == "Default" ]]; then
  echo "No persistent cache — flush is request-scoped only."
else
  wp cache flush
  echo "Persistent cache flushed: $TYPE"
fi

Cache Type Comparison​

TypePersists Between RequestsShared Across ServersRecommended
Default❌ No❌ NoDev only
Redis✅ Yes✅ Yes (single instance)Production
Memcached✅ Yes✅ Yes (cluster)Production

Best Practices​

  1. Always check cache type before flush debugging — if Default, wp cache flush has no meaningful effect between real requests.
  2. Use Redis on all production WordPress sites — it dramatically reduces database load.
  3. Include cache type in server audits — a site running Default on a high-traffic host is a common performance gap.

Quick Reference​

wp cache type                         # Check active cache backend
wp cache flush                        # Flush cache after confirming backend
wp plugin list | grep cache           # Find installed cache plugins

Next Steps​