ShortPixel Critical CSS


With ShortPixel Critical CSS plugin, your website can automatically generate above-the-fold CSS for your web pages.
This means your website will load faster and get better scores with online testing tools like PageSpeed Insights or GTmetrix.

How it works?

  • ShortPixel’s Critical CSS (CCSS) plugin uses our brand new service to generate the critical CSS for your website’s pages.
  • The generated CCSS is inserted into the web pages while the original .css files are deferred. This makes the pages load faster.
  • The plugin starts generating the CCSS for each visited page and retrieves it from the ShortPixel Critical CSS Service. This is done using WP CRON jobs that run in the background without user intervention and without slowing down the website.
  • The edited pages will have the CCSS automatically generated.


  • The CCSS plugin can be configured to keep Critical CSS rules based on the page URL or for each page template. This can help optimize the number of CCSS files needed.
  • Additional flexibility: the website administrator can manually configure additional Critical CSS rules to be included in the generated Critical CSS.
  • Our plugin integrates with WP Rocket and Elementor, if they are present, in order to leverage the cache support and deliver Critical CSS more effectively.

The plugin was forked from the WP Critical CSS plugin, modified to use ShortPixel’s Critical CSS service and enhanced with new features.

Currently, the plugin while in its BETA version, is 100% free to use. Just install it on your website, configure it and test the results with a tool like Google PageSpeed Insights or GTMetrix

For questions or support, please contact us directly here

Other plugins by ShortPixel


  • Settings page (Settings > ShortPixel Critical CSS)

  • Processed pages log (Settings > ShortPixel Critical CSS > Processed log tab)


Just search for “ShortPixel Critical CSS” in the plugin section of your website and install it as you would do with any other plugin.


Is this plugin free?

As long as the plugin is in the BETA testing phase, it is completely free to use.

How can I report a problem?

Go to our contact page.

Does this work inside paywalls or membership websites/pages?

Not at this time. Since cannot currently access protected websites, the webpage must be publicly visible to work. Depending on demand, we may add a feature to allow use on protected websites/pages as well.

What happens if I update the site content or change my theme?

The plugin’s css cache is automatically purged for that post or term, and queued again the next time the user requests it.

What happens when I update a plugin or theme?

The entire cache is flushed, regardless of the purge setting.

Does this support all caching plugins?

Currently only WP-Rocket is supported. Others can be added as integrations upon request.

Which host is supported?

In general, any host. Some hosts like WPEngine provide special support for server cache cleanup.

What does the ‘/nocache/’ in the queued URLs mean?

This is used as a special version of the web page that forcibly disables supported caching and minify plugins to ensure critical CSS is created without complications. From an SEO perspective, these URLs are safe because they are not referenced anywhere and Google cannot crawl them.

Where do I report security bugs found in this plugin?

Please report security bugs found in the source code of the ShortPixel Critical CSS plugin through the Patchstack Vulnerability Disclosure Program. The Patchstack team will assist you with verification, CVE assignment, and notify the developers of this plugin.


December 15, 2023 1 reply
I don’t know of any similar plugin with this functionality. Their service actually analyzes CSS and JS files for which parts can be loaded upfront to make the website show up faster. Only later the full CSS/JS seem to load. For JS files I see that they generate a custom version. Options can be a bit confusing but their customer support is outstanding!
September 19, 2023 3 replies
I keep trying to generate Critical CSS with it but it adds nothing to the queue. I tried it about 5 minutes and uninstalled it. I now understand that pages need to be first visited and I have seen it had some pages in pending. However it seems to return a critical error when I clear cache with WP-Rocket and I can’t troubleshoot the issue and I have deleted the plugin. Although not ideal, I’ll leave 5 stars because I can’t delete this review and I don’t want to negatively impact your rating because of my mistake of not creating a support thread instead.
Read all 3 reviews

Contributors & Developers

“ShortPixel Critical CSS” is open source software. The following people have contributed to this plugin.


“ShortPixel Critical CSS” has been translated into 1 locale. Thank you to the translators for their contributions.

Translate “ShortPixel Critical CSS” into your language.

Interested in development?

Browse the code, check out the SVN repository, or subscribe to the development log by RSS.



Release date: April 29, 2024
* Tweak: Added a “Remove Expired” button to clear the processed log of entries older than 30 days;
* Fix: Updated the text domain of the plugin to correct internationalization;
* Language: 3 new strings added, 1 updated, 0 fuzzed and 0 deprecated.


Release date: April 8, 2024
* Fix: Patched a Broken Access Control vulnerability, found by the PatchStack team (thanks!);
* Fix: Increased the overall security of the plugin by adding sanitization, nonce check and authorization.
* Language: 0 new strings added, 0 updated, 0 fuzzed, and 0 deprecated.


Release date: January 18, 2024
* Fix inlining style that contains “\0” escape sequences, eg. content: “\00a0”;


Release date: September 28, 2023
* New: added a note that the website must be visited for the plugin to generate the critical CSS;
* Fix: fully tested with PHP 8.1 & 8.2, no more deprecation warnings;
* Fix: a fatal error was triggered with PHP 5.6 and older WordPress versions due to a missing function;
* Fix: a critical error was thrown when used with WP Rocket on WP Engine;
* Language: 0 new strings added, 1 updated, 0 fuzzed, and 0 deprecated.


Release date: March 15, 2023
* New: Added support for generating Critical CSS per post type (including custom post types);
* New: When you change the theme, the Critical CSS cache is automatically purged;
* New: Added a button in the settings to clear the CSS cache;
* New: Added the “Delete” action for the API Queue;
* New: Actions similar to those for the API queue have been added for the WebCheck queue;
* New: API key detection when using other ShortPixel plugins;
* New: added help contact form for easier support requests;
* Tweak: Improved the appearance of the generated CSS in the Processed Log pop-up;
* Tweak: When selecting cache methods for WordPress templates or Custom Post Types, all suboptions are enabled by default;
* Fix: Various improvements to the WebCheck and API queues, as well as the Processed Log;
* Fix: Some links were getting a double nocache at the end, resulting in a 404 when trying to generate the Critical CSS;
* Fix: Caching settings are no longer lost after switching themes;
* Fix: WP Cron notification can now be dismissed;
* Fix: Updated the texts and improved the general appearance of the plugin settings page;


  • Fix warning when Fallback CSS not set


  • Initial version