A must-use plugin (also called a ‘mu-plugin’) is a plugin that will always be activated by default, without you needing to do it yourself. To activate a mu-plugin, you just have to upload it in the right directory, and WordPress will automatically know that this plugin must be used. Moreover, a mu-plugin cannot be deactivated: it will always be executed, unless it is uninstalled.
Originally, mu-plugins were only available for WPMU, for those sites which used multiple (multisite) blogs. Back then, a mu-plugin was just a plugin activated for all blogs.
Fun fact, that the WordPress is loading mu-plugins in alphabetical order, before normal plugins.
All mu-plugins must be placed at wp-content/mu-plugins by default, in case /mu-plugins/ folder is not there, feel free to create it.
Add CSS code in mu-plugin
Create a file named style.php and add the following code inside.
<?php add_action( 'wp_head', function() { ?> <style> /* YOUR CSS CODE GOES HERE*/ </style> <?php } );
Add your CSS code between
<style></style>
tags.
Fell free to comment bellow if you have something new to add 🙂
Simple and effective … great!
Thanks!
I tried this and can’t get it to work. Can you use hooks in the mu-plugins?
to do it? It wouldn t be any different to a regular plugin, except that MU plugins are a single PHP file only, so you d need to write the CSS in a PHP function, or store the CSS file somewhere else. Jacob Peattie Sep 18 at 8:58