Daniele De Santis

WP Add Custom CSS allows you to add custom CSS to the whole website and to individual posts, pages and custom post types (such as Woocommerce products). 
The CSS rules applied to the whole website will override the default stylesheets of your theme and plugins, while the CSS rules applied to specific pages, posts or custom post types will override the main stylesheet too.
The plugin works with the most popular builders, such as Elementor, Gutenberg and the Classic Editor.
You can edit the main stylesheet from the the “Add custom CSS” settings page. 
The plugin also creates a new “Custom CSS” box in the editing area to add custom CSS to specific posts, pages and custom post types.
Select the preferred CSS output method from the plugin’s settings page to ensure seamless integration with caching and minification plugins or to improve above-the-fold rendering performance.

WP Add Custom CSS


Says it has not been tested against recent versions, but it works great still. Simple and elegant solution. Sep 13 2024


Still works great

Add custom css to the whole website and to specific posts and pages.

esthertyler

Transfered to new dev: https://profiles.wordpress.org/esthertyler
Maked by Esther Tyler: http://mycustomcss.com/
With this plugin you can put custom css code without edit your theme and/or your plugins (really useful in case of any theme/plugin update).
It contain also <a href="https://ace.c9.io/" rel="nofollow ugc">Ace (Ajax.org Cloud9 Editor)</a> Code Editor for write a good css code.
You can see in action (source code) here: <a href="http://www.vegamami.it/" rel="nofollow ugc">VegAmami</a> 🙂
PS: support file backup and – very important – static css file (fantastic for performance) 😉
<h4>Links</h4>
<ul>
<li>New dev: https://profiles.wordpress.org/esthertyler</li>
<li>Author Homepage: <a href="http://mycustomcss.com/" rel="nofollow ugc">Esther Tyler</a></li>
<li>Plugin maked for (demo link): <a href="http://www.vegamami.it/" rel="nofollow ugc">VegAmami</a></li>
<li>Ace (Ajax.org Cloud9 Editor): <a href="https://ace.c9.io/" rel="nofollow ugc">Ace (Ajax.org Cloud9 Editor)</a></li>
</ul>
<h4>Language</h4>
<ul>
<li>English</li>
<li>Italian</li>
<li>Full translatable!</li>
</ul>

My Custom CSS PHP & ADS

Enable to add Custom CSS Code via admin panel with Ace (Ajax.org Cloud9 Editor) + backup (see screen) and static file cache (best performance) :)

WP Add Custom CSS vs My Custom CSS PHP & ADS