This plugin hasn’t been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.

APCu Object Cache Backend


Using this Plugin WordPress is able to store certain regular used elements into a persistent cache. Instead of computing complex operations over and over again on every single page request, its result is stored in memory once and from then on fetched directly from the cache on future page requests.

Such an object cache will reduce access to your database and speed up page loading.

This implementation uses APCu‘s variable cache as backend.


  1. You need to install and configure the APCu PHP extension.
  2. Download and extract the content of the archive file.
  3. Upload the file object-cache.php of this plugin into your /wp-content/ directory. Note that this file needs to be stored directly into your content directory and not under the plugins directory.
  4. This plugin should now work without any further configuration. Check if it is listed under Plugins -> Installed Plugins -> Drop-ins.


“Cannot redeclare wp_cache_add()…”

This error indicates that you likely have two copies of the object cache installed. Make sure you have put the file object-cache.php into your /wp-content/ directory only. Do not upload it to the /wp-content/plugins directory or any subdirectory like /wp-content/plugins/apcu. The APCu Object Cache Backend is not a regular WordPress plugin but a Drop-in. Therefore you cannot store it into the plugins directory.


Plugin no longer supported – Breaks Caching

We're unable to see updates on our website, we can't remove this plugin (the files don't exist where they should)...even deleting images still shows the image, regardless of flushing cache, changing browsers, etc... Use at your own risk, this plugin appears abandoned.
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Contributors & Developers

“APCu Object Cache Backend” is open source software. The following people have contributed to this plugin.




  • Minor code improvements
  • Compatibility with PHP 7.1 and WordPress 4.7


  • WordPress 4.4 support
  • Compatibility with PHP 7 and APCu 5


  • WordPress 4.3 support


  • initial version