Derrick Hammer

This plugin will automatically have the CriticalCSS.com web service get the needed above the fold CSS for every page on your site to help improve your user experience and site speed. This is commonly required by google pagespeed as one of the last steps to do.
This plugin alone will not improve site performance. You need a minify and/or caching plugin as well.
This plugin does not handle any minification or re-ordering of assets. I recommend using <a href="https://wp-rocket.me/" rel="nofollow ugc">WP Rocket</a> with my <a href="https://wordpress.org/plugins/rocket-footer-js/">WP Rocket Footer JS</a>, <a href="https://wordpress.org/plugins/rocket-async-css/">WP Rocket ASYNC CSS</a>, and the plugin <a href="https://wordpress.org/plugins/the-preloader/">Preloader</a>
If you are looking for a professional team to get your WordPress site to run faster, check us out for our speed optimization services at <a href="https://rankgrowdigital.com/" rel="nofollow ugc">Rank Grow Digital</a>

WP Critical CSS

Triggers a fatal PHP error:

Fatal error: Uncaught ArgumentCountError: array_merge() does not accept unknown named parameters in public_html/wp-content/plugins/wp-criticalcss/lib/WP/CriticalCSS/Request.php:119

Cannot activate

WordPress plugin that will use CriticalCSS.com to automatically generate above-the-fold CSS for your pages.

Frank Goossens

Deny Dias

This plugin extends Autoptimize to automatically create critical CSS rules. These rules inject the correct critical CSS in different types of pages to ensure these pages are rendered even before the full CSS is loaded, improving the “start to render time” and user experience. For this purpose the plugin integrates with criticalcss.com, a 3rd party service, to have it generate the critical CSS (see <a href="https://wordpress.org/plugins/autoptimize-criticalcss/#faq">FAQ for info on pricing</a>).
Simply install and activate the plugin (you will need to have Autoptimize up and running), enter your <a href="https://criticalcss.com/?aff=1" rel="nofollow ugc">https://criticalcss.com</a> API key and the plugin will automatically start work to create rules.
If you want to change settings or review the rules, you can find these by clicking the “critical css” tab on the Autoptimize plugin settings screen. There are “installation instructions” and more info in <a href="https://wordpress.org/plugins/autoptimize-criticalcss/#faq">the FAQ</a>.

Autoptimize criticalcss.com power-up

Its configuration definitely has a learning curve, but when you get the hang of it, this plugin becomes essential to your website!

Close to perfect

Autoptimize criticalcss.com power-up adds automated critical css creation to Autoptimize integrating with the https://criticalcss.com service.

WP Critical CSS vs Autoptimize criticalcss.com power-up