Add Admin JavaScript


Ever want to introduce custom dynamic functionality to your WordPress admin pages and otherwise harness the power of JavaScript? Any modification you may want to do with JavaScript can be facilitated via this plugin.

Using this plugin you’ll easily be able to define additional JavaScript (inline and/or by URL) to be added to all administration pages. You can define JavaScript to appear inline in the admin head, admin footer (recommended), or in the admin footer within a jQuery jQuery(document).ready(function($)) {} section, or reference JavaScript files to be linked in the page header. The referenced JavaScript files will appear in the admin head first, listed in the order defined in the plugin’s settings. Then any inline admin head JavaScript is added to the admin head. All values can be filtered for advanced customization (see Filters section).

Links: Plugin Homepage | Plugin Directory Page | Author Homepage


The plugin exposes four filters for hooking. Typically, these customizations would be put into your active theme’s functions.php file, or used by another plugin.

c2c_add_admin_js_files (filter)

The ‘c2c_add_admin_js_files’ hook allows you to programmatically add to or
customize any referenced JavaScript files defined in the “Admin JavaScript Files” field.


  • $files (array): Array of JavaScript files


add_filter( 'c2c_add_admin_js_files', 'my_admin_js_files' );
function my_admin_js_files( $files ) {
    $files[] = '';
    return $files;

c2c_add_admin_js_head (filter)

The ‘c2c_add_admin_js_head’ hook allows you to programmatically add to or
customize any JavaScript to be put into the page head as defined in the
“Admin JavaScript (in head)” field.


  • $js (string): JavaScript


add_filter( 'c2c_add_admin_js_head', 'my_add_head_js' );
function my_add_head_js( $js ) {
    $js .= "alert('Hello');";
    return $js;

c2c_add_admin_js_footer (filter)

The ‘c2c_add_admin_js_footer’ hook allows you to programmatically add to or
customize any JavaScript to be put into the page head as defined in the
“Admin JavaScript (in footer)” field.


  • $js (string): JavaScript


add_filter( 'c2c_add_admin_js_footer', 'my_add_footer_js' );
function my_add_footer_js( $js ) {
    $js .= "alert('Hello');";
    return $js;

c2c_add_admin_js_jq (filter)

The ‘c2c_add_admin_js_jq’ hook allows you to filter the jQuery JavaScript to be output in the footer of admin pages.
The ‘c2c_add_admin_js_jq’ hook allows you to programmatically add to or
customize any jQuery JS to be put into the page footer as defined in the
“Admin jQuery JavaScript” field.


  • $js_jq (string): String of jQuery JavaScript


add_filter( 'c2c_add_admin_js_jq', 'my_add_jq' );
function my_add_jq( $js_jq ) {
    $js_jq .= "$('.hide_me').hide();";
    return $js_jq;


  • A screenshot of the plugin's admin settings page.


  1. Unzip inside the /wp-content/plugins/ directory for your site (or install via the built-in WordPress plugin installer)
  2. Activate the plugin through the ‘Plugins’ admin menu in WordPress
  3. Go to “Appearance” -> “Admin JavaScript” and add some JavaScript to be added into all admin pages.


Can I add JavaScript I defined via a file, or one that is hosted elsewhere?

Yes, via the “Admin JavaScript Files” input field on the plugin’s settings page.

Can I limit what admin pages the JavaScript gets output on?

No, not presently. At least not directly. By default, the JavaScript is added to every admin page on the site.

However, you can preface your selectors with admin page specific class(es) on ‘body’ tag to ensure CSS only applies on certain admin pages. (e.g. jQuery('body.index-php h2').hide();).

Or, you can hook all the plugin’s filters and determine the current admin page content to decide whether the respective hook argument should be returned (and thus output) or not.

Can I limit what users the JavaScript applies to?

No, not presently. At least not directly. By default, the JavaScript is added for any user that can enter the admin section of the site.

You can hook all the plugin’s filters and determine the current user to decide whether the respective hook argument should be returned (and thus output) for the user or not.

Does this plugin include unit tests?



so simple, yet so powerful

I was looking for a way of adding my own simple JS code into WP admin, without getting into system files, messing things up and what not.
As I was looking for this online, I quickly came across this plugin, and it does exactly what I was looking for, no huss, no fuss.
Well done for this plugin! Two thumbs up!

crashed WordPress 4.5

It crashed WordPress 4.5 by:

Fatal error: Call to undefined function get_userdata() in /public_html/wp-includes/user.php on line 458

Read all 4 reviews

Contributors & Developers

“Add Admin JavaScript” is open source software. The following people have contributed to this plugin.


Translate “Add Admin JavaScript” into your language.

Interested in development?

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


1.4 (2016-01-12)

* This release fixes a couple of bugs, adds support for language packs, and has many minor behind-the-scenes changes.

* Bugfix: Allow CSS links/files with query args to be enqueued.
* Bugfix: If specified as part of the link, ‘ver’ query arg takes precedence as script version.
* Add: More unit tests.
* Add: Amend a couple of the FAQ answers to indicate things are possible via hooks rather than suggesting they aren’t possible.
* Change: Update plugin framework to 040:
* Change class name to c2c_AddAdminCSS_Plugin_040 to be plugin-specific.
* Set textdomain using a string instead of a variable.
* Don’t load textdomain from file.
* Change admin page header from ‘h2’ to ‘h1’ tag.
* Add c2c_plugin_version().
* Formatting improvements to inline docs.
* Change: Add support for language packs:
* Set textdomain using a string instead of a variable.
* Remove .pot file and /lang subdirectory.
* Change: Declare class as final.
* Change: Explicitly declare methods in unit tests as public or protected.
* Change: Minor tweak to description.
* Change: Minor improvements to inline docs and test docs.
* Add: Create empty index.php to prevent files from being listed if web server has enabled directory listings.
* Change: Note compatibility through WP 4.4+.
* Change: Remove support for versions of WordPress older than 4.1.
* Change: Update copyright date (2016).

1.3.4 (2015-04-30)

  • Bugfix: Fix line-wrapping display for Firefox and Safari
  • Enhancement: Add an additional unit test
  • Update: Move ‘Advanced’ section lower in readme; add inline docs to example code
  • Update: Note compatibility through WP 4.2+

1.3.3 (2015-02-21)

  • Bugfix: Revert back to using dirname(__FILE__); __DIR__ is only PHP 5.3+

1.3.2 (2015-02-16)

  • Update plugin framework to 039
  • Add to and improve unit tests
  • Explicitly declare class method activation() and uninstall() static
  • Use DIR instead of dirname(__FILE__)
  • Various inline code documentation improvements (spacing, punctuation)
  • Note compatibility through WP 4.1+
  • Update copyright date (2015)
  • Regenerate .pot

1.3.1 (2014-08-25)

  • Update plugin framework to 038
  • Minor plugin header reformatting
  • Minor code reformatting (spacing, bracing)
  • Change documentation links to to be https
  • Localize an additional string
  • Note compatibility through WP 4.0+
  • Regenerate .pot
  • Add plugin icon

1.3 (2014-01-03)

  • Fix enqueuing multiple JS files by generating unique handle for each
  • Fix enqueuing of local files when not prepended with forward slash
  • Add unit tests
  • Update plugin framework to 036
  • Improve URL path construction
  • Use explicit path for require_once()
  • Add reset() to reset object to its initial state
  • Remove __clone() and __wake() since they are part of framework
  • For options_page_description(), match method signature of parent class
  • Note compatibility through WP 3.8+
  • Drop compatibility with versions of WP older than 3.5
  • Update copyright date (2014)
  • Change donate link
  • Minor readme.txt tweaks (mostly spacing)
  • Add banner
  • Update screenshot


  • Move ‘Advanced Tips’ section from bottom of settings page into contextual help section
  • Add help_tabs_content() and contextual_help()
  • Prevent textareas from wrapping lines
  • Change input fields to be displayed as inline_textarea instead of textarea
  • Add instance() static method for returning/creating singleton instance
  • Made static variable ‘instance’ private
  • Add dummy __clone() and __wakeup()
  • Remove c2c_AddAdminJavaScript(); only PHP5 constructor is supported now
  • Update plugin framework to 035
  • Discontinue use of explicit pass-by-reference for objects
  • Add check to prevent execution of code if file is directly accessed
  • Regenerate .pot
  • Re-license as GPLv2 or later (from X11)
  • Add ‘License’ and ‘License URI’ header tags to readme.txt and plugin file
  • Minor documentation improvements
  • Note compatibility through WP 3.5+
  • Drop compatibility versions of WP older than 3.1
  • Update copyright date (2013)
  • Minor code reformatting (spacing)
  • Remove ending PHP close tag
  • Create repo’s assets directory
  • Move screenshot into repo’s assets directory


  • Fix typo in code example in Advanced Tips
  • Add addition help text for js_head to indicate use of js_foot is preferred
  • Update .pot
  • Update screenshot


  • Update plugin framework to 029
  • Save a static version of itself in class variable $instance
  • Discontinue use of global variable $c2c_add_admin_js to store instance
  • Explicitly declare all functions as public
  • Add __construct(), activation(), and uninstall()
  • Note compatibility through WP 3.3+
  • Drop compatibility with versions of WP older than 3.0
  • Expand most onscreen and documentation references from “JS” to “JavaScript”
  • Add .pot
  • Add screenshot
  • Add ‘Domain Path’ plugin header
  • Tweak description
  • Minor code formatting changes (spacing)
  • Update copyright date (2011)
  • Add plugin homepage and author links in description in readme.txt


  • Initial release (not publicly released)