Admin CSS MU – Load an Admin Side CSS For Customizing WP-Admin

Admin CSS MUI had written on how to load CSS on the admin side before. This involved adding the load function into the functions.php of the theme.

Recently a need arose where the CSS had to be loaded irrespective of the theme being used, on a multisite network. So the function took shape as a plugin and I have my first WordPress plugin up in the extend.

Admin CSS MU

Admin CSS MU simply loads a CSS file. All your custom CSS can go into that file. I think the best use case for the plugin would be as a mu plugin, since it wouldn’t probably need an update ever (and hence the MU in the name).

Installation Instructions:

To use as a normal plugin in WordPress single install and Multisite.

  • Install the plugin through the WordPress admin interface, or upload the folder /admin-css-mu/ to wp-content/plugins/ using ftp.
  • Move (or create) custom_admin.css to wp-content/themes/ folder. (it should look like wp-content/themes/custom_admin.css)
  • Add the custom css you want into custom_admin.css.
  • Activate the plugin via WordPress admin interface. If it is a Multisite, preferably Network Activate it.

To use as a Must Use (mu) plugin for WordPress single install and Multisite.

  • If you don’t have already, create a folder /mu-plugins/ in /wp-content/ directory on your server. (it should look like wp-content/mu-plugins/)
  • Upload the file (just the file, not folder) admincssmu.php to wp-content/mu-plugins/ . (it should look like wp-content/mu-plugins/admincssmu.php)
  • Move (or create) custom_admin.css to wp-content/themes/ folder. (it should look like wp-content/themes/custom_admin.css)
  • No activation is necessary. MU plugins are always active and can only be deactivated if you delete it. No auto-updates are available though.

Plugin Page | Download | CSS Samples

Hope you find this useful. Let me know what you think. Cheers!

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  1. Karan says:

    This is great. Having your custom CSS file get uploaded is awesome. Thanks Arun, really helpful for our web designers team.

  2. Jungleads says:

    This was a great plugin really nice keep up your good work,please do develop more usefull plugins.

    Thanks again.

  3. chandan says:

    thanks a lot sharing this works well…

  4. Nazmul says:

    Oh! Nice plugin..thanks

  5. Lizee Helene says:

    worked well!!
    Thanks for sharing mate!

  6. George says:

    Did you made this plugin? That’s really cool. I would love to see more of your developed plugins.

  7. Maadhav Saxena says:

    Nice plug-in! Just added it and it works like a charm! Thanks

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