This Comet Cache release candidate includes 1 bug fix, 7 enhancements, 1 new Pro feature, and compatibility and documentation improvements. You can download and try out this release using the link below. Please report bugs and feedback on GitHub.

Comet Cache Pro testers: Don't forget that you can automatically receive Release Candidates by telling the Comet Cache Plugin Updater to check for Release Candidates in Comet Cache → Plugin Options → Update Credentials → Beta Program.


Lite: Comet Cache Lite v161214-RC

Pro: Comet Cache Pro v161214-RC (you must be logged into your account at to access this download)

Installation Instructions

  1. Deactivate and Delete any existing Comet Cache 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 Comet Cache

Changelog for Comet Cache v161214-RC (Release Candidate)

  • Bug Fix: Improving OPcache detection. Now considering INI option opcache.restrict_api. Comet Cache is now smart enough to avoid the error: PHP Warning: Zend OPcache API is restricted by "restrict_api" configuration directive. See Issue #733.

  • New Feature (Pro): Mobile Mode. This release adds a new feature that is designed to improve compatibility with Adaptive themes for mobile devices. To learn more, please see: WordPress Dashboard Comet Cache Pro Plugin Options Mobile Mode. See also: Issue #471 and the screenshots here.

  • Enhancement: Auto-Clearing Author Page Cache. This release makes Comet Cache smart enough to detect when a user is deleted (or removed from a child blog in a Network), at which time the Author page for that user will be cleared from the cache so it can be regenerated automatically. See Issue #304.

  • Enhancement: Multibyte Compatibility. This release improves support for WordPress Permalinks that contain UTF-8 symbols (or emojis) in them. More specifically, this release adds the /u flag to all preg_*() calls in cache clearing routines that generate cache paths from Watered-Down Regex patterns entered by a site owner. See: Issue #611.

  • Enhancement: Widget Change Detection. Comet Cache can now detect when Appearance → Widgets are added/edited/removed, and Comet Cache will automatically clear the cache so that your site remains up-to-date. See Issue #411.

  • Enhancement (Pro): Static CDN Filters and srcset. This release enhances Static CDN Filters in Comet Cache Pro. Static CDN Filters are now smart enough to filter all image sources included in an srcset="" attribute that is generated by WordPress. See Issue #660. If you'd like to learn more about srcset="", see this article at

  • Enhancement (Pro): Automatic Background Updates. It is now possible to enable automatic background updates that occur quietly in the background whenever new features, bug fixes, or security issues are addressed by our developers. See: WordPress Dashboard Comet Cache Pro Config. Options Update Credentials. See also: Issue #827.

  • Enhancement (Pro): HTML Compressor + Accelerated Mobile Pages (AMP). Updated to the latest available release of the HTML Compressor (v161208) with improved support for Accelerated Mobile Pages. See: Issue #695. See also: HTML Compressor v161208 changelog.

  • Enhancement (Pro): HTML Compressor / AMP Compatibility. Improved compatibility with Accelerated Mobile Pages. There is a new HTML Compressor option that is enabled by default and it makes Comet Cache smart enough to auto-detect and selectively disable portions of the HTML Compressor that are incompatible with the AMP spec; i.e., routines that are not necessary when serving APMd pages. In short, if the URI being compressed ends with /amp/, or the document contains a top-level <html ⚡> tag (<html amp> is accepted as well), then features which are incompatible with Accelerated Mobile Pages will be disabled accordingly.

  • Compatibility: Avoid deprecated wp_get_sites() and use get_sites() instead. See Issue #848.

  • Documentation: Added Watered-Down Regex documentation notes to the inline documentation (in the software) about the use of ^ and $ in some places where these special characters are not fully supported. Also adding the same notes to the Watered-Down Regex KB Article. See also: Issue #611.

Please note that when this version leaves beta and an official release is made, the WordPress Plugin Updater will automatically detect the new version on and ask you to upgrade (applies to Comet Cache Lite). If you're using Comet Cache Pro, please configure the Pro Plugin Updater (Dashboard → Comet Cache → Plugin Updater) so that you are notified when there is a new official release.

Please report bugs and feedback on GitHub.