This ZenCache release candidate includes 5 new features, 5 bug fixes, and 3 enhancements. The most notable addition is a brand new feature called Cache Statistics which helps you monitor the state of your WordPress cache. We've also added the highly-requested ability to specify which WordPress Roles/Capabilities are allowed to clear the cache. You can download and try out this release using the link below. Please report bugs and feedback on GitHub.


Download ZenCache Pro v150919 Release Candidate (you must be logged into your account at to access this download)

Installation Instructions

  1. Deactivate and Delete any existing ZenCache plugin via Dashboard -> Plugins
  2. Download the release candidate using the link above
  3. Install the release candidate you downloaded by going to Dashboard -> Plugins -> Add New -> Upload and selecting the downloaded zip file
  4. Activate ZenCache

Changelog for ZenCache v150919 (Release Candidate)

  • New Feature! Cache Statistics is a completely new ZenCache Pro feature that will help site owners better understand their WordPress site cache. An easy-to-access Cache Stats menu button in the Admin Bar is accompanied by a whole new page that shows Current Cache Totals (including total number of cache files and total size of cache on the disk), Current Disk Health (including total disk capacity and total available), Current System Health (including memory usage and load average), and two beautiful Polar Area pie charts that show you both current and historical data on Cache File Counts and Cache File Sizes with a 30-Day High, Current Total, Page Cache total, and HTML Compressor total for each chart. Props to @jaswsinc. See Issue #83.
  • New Feature! It's now possible to specify which WordPress Roles/Capabilities are allowed to clear the cache from the WordPress Admin bar. A new option inside Dashboard → ZenCache → Plugin Options → Manual Cache Clearing allows specifying a comma-delimited list of Roles and/or Capabilities under, "Also allow others to clear the cache from their Admin Bar?". If a user has an allowed Role/Capability, they will see the "Clear Cache" button in their Admin Bar. This feature is also compatible with WordPress Multisite Networks, allowing a Network Administrator to define which Child Site roles should allow a Child Site user to see the "Clear Cache" button for their Child Site. Props @danielmt2k @jaswsinc. See Issue #68.
  • New Feature! It's now possible to "Disable Cache Expiration If Server Load Average is High" (see Dashboard → ZenCache → Plugin Options → Cache Expiration Time). This allows you to provide a specific load average that should cause ZenCache to disable cache expiration and help reduce stress on the server; i.e., to avoid generating a new version of the cache while the server is very busy. Props @jaswsinc. See Issue #347.
  • New Feature! It's now possible to manually clear the CDN Cache when Static CDN Filters are enabled. Inside the Static CDN Filters options panel there's a new "Clear CDN Cache" button and there's also a new option ("Clear the CDN Cache Too?") inside Dashboard → ZenCache → Plugin Options → Manual Cache Clearing that allows you to specify whether or not you'd like the CDN Cache to be cleared whenever the "Clear Cache" button is clicked (either from the Admin Bar or from inside the Plugin Options). Props @kristineds @jaswsinc. See Issue #488.
  • New Feature! When your server has the PHP OPCache Extension installed, ZenCache can now be configured to also clear the PHP opcode cache whenever you clear the cache manually using the ZenCache "Clear Cache" button. See ZenCache Options → Manual Cache Clearing → Clear the PHP OPCache Too? (note that this option only appears if you have the OPCache Extension installed). Props @jaswsinc. See Issue #489.
  • Bug Fix: Fixed an HTML Compressor bug related to CSS pseudo-classes where spaces between the class name and pseudo-class name were being removed when CSS was minified. Props @patdumond @jaswsinc. See Issue #544.
  • Bug Fix: Fixed an HTML Compressor bug related to <noscript> tags. The HTML Compressor now makes no adjustments to anything inside <noscript> tags, and the same has always been true for IE conditional comments as well. Props @rtrevellyan @jaswsinc. See Issue #65.
  • Bug Fix: Fixed an issue related to a popular NGINX server configuration (try_files $uri $uri/ /index.php?q=$uri&$args;) that was preventing the entire site from being cached. ZenCache disables caching by default for all requests that include a query string (see Dashboard → ZenCache → Plugin Options → GET Requests) and this particular NGINX configuration passes all requests to WordPress with a ?q= query variable, which was resulting in ZenCache disabling caching on all pages. This release implements better detection for NGINX and works around this scenario. Props @jaswsinc. See Issue #561.
  • Bug Fix: Fixed a bug with the Static CDN Filters that affected sites using a permalink structure that ended with .htm or .html. Generally, files that end in .htm or .html are considered static files, hence the reason ZenCache was rewriting URLs with those extensions to point at the configured CDN. However, if a site uses .htm or .html in their permalink structure, all links to Posts/Pages within the site will appear to be static files when they are in fact dynamic and therefore should not be rewritten. ZenCache now checks the permalink structure and excludes .htm and .html from the allowed extensions when the permalink structure is using one of these. Props @jaswsinc. See Issue #495.
  • Multisite Bug Fix: Fixed a bug in the Auto-Cache Engine that was resulting in duplicate Cron Jobs being created for each Child Site. The Auto-Cache Engine now only runs from the Main Site in a network, as it should. When the Auto-Cache Engine runs on the Main Site, it will also run for each of the Child Blogs (see this article for more information). Props @jaswsinc. See Issue #543.
  • Enhancement: Improved HTML Compressor HTTP connection handling, timeouts, protocol, BOM markers, exceptions, Referer: and User-Agent: headers. Props @LittleBastard77 @jaswsinc. See Issue #391 and Issue #69.
  • Enhancement: Manual Cache Clearing options have now been separated from Automatic Cache Clearing options inside the ZenCache Plugin Options to improve the differentiation between these.
  • Enhancement: New icons in the ZenCache Plugin Options help improve the visual representation of each panel.

Please note that when this version leaves beta and an official release is made, the ZenCache Pro Plugin Updater will automatically detect the new version and ask you to upgrade. You must configure the Pro Plugin Updater (Dashboard -> ZenCache -> Plugin Updater) to be notified when there is a new official release.

Please report bugs and feedback on GitHub.