wp_register_script( string $handle, string|false $src, string[] $deps = array(), string|bool|null $ver = false, array|bool $args = array() ): bool

Registers a new script.


Registers a script to be enqueued later using the wp_enqueue_script() function.

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See also

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$handle string Required
Name of the script. Should be unique.
$src string|false Required
Full URL of the script, or path of the script relative to the WordPress root directory.
If source is set to false, script is an alias of other scripts it depends on.
$deps string[] Optional
An array of registered script handles this script depends on.

Default: array()

$ver string|bool|null Optional
String specifying script version number, if it has one, which is added to the URL as a query string for cache busting purposes. If version is set to false, a version number is automatically added equal to current installed WordPress version.
If set to null, no version is added.

Default: false

$args array|bool Optional
An array of additional script loading strategies.
Otherwise, it may be a boolean in which case it determines whether the script is printed in the footer. Default false.
  • strategy string
    Optional. If provided, may be either 'defer' or 'async'.
  • in_footer bool
    Optional. Whether to print the script in the footer. Default 'false'.

Default: array()

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bool Whether the script has been registered. True on success, false on failure.

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More Information

Scripts that have been pre-registered using wp_register_script() do not need to be manually enqueued using wp_enqueue_script() if they are listed as a dependency of another script that is enqueued. WordPress will automatically include the registered script before it includes the enqueued script that lists the registered script’s handle as a dependency.

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wp_register_script( $handle, $src, $deps, $ver, $args );

  • Registering scripts is technically not necessary, but highly recommended nonetheless.
  • If the handle of a registered script is listed in the $deps array of dependencies of another script that is enqueued with wp_enqueue_script(), that script will be automatically loaded prior to loading the enqueued script. This greatly simplifies the process of ensuring that a script has all the dependencies it needs. See below for a simple example.
  • So, the main purpose of the register functions is to allow you to simplify your code by removing the need to duplicate code if you enqueue the same script or style in more than one section of code. The benefits of this are many and probably don’t need to be listed here.
  • As of WordPress 6.3, the new $args parameter – that replaces/overloads the prior $in_footer parameter – can be used to specify a script loading strategy. See the sections to follow for more information.

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  • The function should be called using the wp_enqueue_scripts or init action hook if you want to call it on the front-end of the site. To call it on the administration screens, use the admin_enqueue_scripts action hook. For the login screen, use the login_enqueue_scripts action hook. Calling it outside of an action hook can often lead to unexpected results and should be avoided.
  • If attempt to register or enqueue an already registered handle with different parameters, the new parameters will be ignored. Instead, use wp_deregister_script() and register the script again with the new parameters.
  • jQuery UI Effects is not included with the jquery-ui-core handle

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Delayed Script Loading

WordPress provides support for specifying a script loading strategy via the wp_register_script() and wp_enqueue_script() functions, by way of the strategy key within the new $args array parameter introduced in WordPress 6.3.

Supported strategies are as follows:

  • defer
    • Added by specifying an array key value pair of 'strategy' => 'defer' to the $args parameter.
    • Scripts marked for deferred execution — via the defer script attribute — are only executed once the DOM tree has fully loaded (but before the DOMContentLoaded and window load events). Deferred scripts are executed in the same order they were printed/added in the DOM, unlike asynchronous scripts.
  • async
    • Added by specifying an array key value pair of 'strategy' => 'async' to the $args parameter.
    • Scripts marked for asynchronous execution — via the async script attribute — are executed as soon as they are loaded by the browser. Asynchronous scripts do not have a guaranteed execution order, as script B (although added to the DOM after script A) may execute first given that it may complete loading prior to script A. Such scripts may execute either before the DOM has been fully constructed or after the DOMContentLoaded event.

Following is an example of specifying a loading strategy during script registration:

        'strategy'  => 'defer',

The same approach applies when using wp_enqueue_script() .

When applying a loading strategy via either the wp_register_script() and wp_enqueue_script() functions, the scripts dependency tree is taken into consideration and the most eligible loading strategy is applied.

While the intended (delayed) strategy passed by the code author may not be the final one, it will never be a stricter one, thus maintaining the integrity of the dependency tree.

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Core-Registered Scripts

By default, WordPress bundles many popular scripts commonly used by web developers besides the scripts used by core itself. Below is an (incomplete) list of the handles and paths of these scripts.

Handle Path in WordPress
utils /wp-includes/js/utils.js
common /wp-admin/js/common.js
sack /wp-includes/js/tw-sack.js
quicktags /wp-includes/js/quicktags.js
colorpicker /wp-includes/js/colorpicker.js
editor /wp-admin/js/editor.js
wp-fullscreen /wp-admin/js/wp-fullscreen.js
wp-ajax-response /wp-includes/js/wp-ajax-response.js
wp-pointer /wp-includes/js/wp-pointer.js
autosave /wp-includes/js/autosave.js
heartbeat /wp-includes/js/heartbeat.js
wp-auth-check /wp-includes/js/wp-auth-check.js
wp-lists /wp-includes/js/wp-lists.js
prototype external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-root external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-builder external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-dragdrop external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-effects external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-slider external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-sound external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous-controls external: //ajax.googleapis.com/ajax/libs/prototype/
scriptaculous scriptaculous-dragdrop, scriptaculous-slider, scriptaculous-controls
cropper /wp-includes/js/crop/cropper.js
jquery (v1.10.2 as of WP 3.8) jquery-core, jquery-migrate
jquery-core /wp-includes/js/jquery/jquery.js
jquery-migrate /wp-includes/js/jquery/jquery-migrate.js (v1.10.2 as of WP 3.8)
jquery-ui-core /wp-includes/js/jquery/ui/jquery.ui.core.min.js
jquery-effects-core /wp-includes/js/jquery/ui/jquery.ui.effect.min.js
jquery-effects-blind /wp-includes/js/jquery/ui/jquery.ui.effect-blind.min.js
jquery-effects-bounce /wp-includes/js/jquery/ui/jquery.ui.effect-bounce.min.js
jquery-effects-clip /wp-includes/js/jquery/ui/jquery.ui.effect-clip.min.js
jquery-effects-drop /wp-includes/js/jquery/ui/jquery.ui.effect-drop.min.js
jquery-effects-explode /wp-includes/js/jquery/ui/jquery.ui.effect-explode.min.js
jquery-effects-fade /wp-includes/js/jquery/ui/jquery.ui.effect-fade.min.js
jquery-effects-fold /wp-includes/js/jquery/ui/jquery.ui.effect-fold.min.js
jquery-effects-highlight /wp-includes/js/jquery/ui/jquery.ui.effect-highlight.min.js
jquery-effects-pulsate /wp-includes/js/jquery/ui/jquery.ui.effect-pulsate.min.js
jquery-effects-scale /wp-includes/js/jquery/ui/jquery.ui.effect-scale.min.js
jquery-effects-shake /wp-includes/js/jquery/ui/jquery.ui.effect-shake.min.js
jquery-effects-slide /wp-includes/js/jquery/ui/jquery.ui.effect-slide.min.js
jquery-effects-transfer /wp-includes/js/jquery/ui/jquery.ui.effect-transfer.min.js
jquery-ui-accordion /wp-includes/js/jquery/ui/jquery.ui.accordion.min.js
jquery-ui-autocomplete /wp-includes/js/jquery/ui/jquery.ui.autocomplete.min.js
jquery-ui-button /wp-includes/js/jquery/ui/jquery.ui.button.min.js
jquery-ui-datepicker /wp-includes/js/jquery/ui/jquery.ui.datepicker.min.js
jquery-ui-dialog /wp-includes/js/jquery/ui/jquery.ui.dialog.min.js
jquery-ui-draggable /wp-includes/js/jquery/ui/jquery.ui.draggable.min.js
jquery-ui-droppable /wp-includes/js/jquery/ui/jquery.ui.droppable.min.js
jquery-ui-menu /wp-includes/js/jquery/ui/jquery.ui.menu.min.js
jquery-ui-mouse /wp-includes/js/jquery/ui/jquery.ui.mouse.min.js
jquery-ui-position /wp-includes/js/jquery/ui/jquery.ui.position.min.js
jquery-ui-progressbar /wp-includes/js/jquery/ui/jquery.ui.progressbar.min.js
jquery-ui-resizable /wp-includes/js/jquery/ui/jquery.ui.resizable.min.js
jquery-ui-selectable /wp-includes/js/jquery/ui/jquery.ui.selectable.min.js
jquery-ui-slider /wp-includes/js/jquery/ui/jquery.ui.slider.min.js
jquery-ui-sortable /wp-includes/js/jquery/ui/jquery.ui.sortable.min.js
jquery-ui-spinner /wp-includes/js/jquery/ui/jquery.ui.spinner.min.js
jquery-ui-tabs /wp-includes/js/jquery/ui/jquery.ui.tabs.min.js
jquery-ui-tooltip /wp-includes/js/jquery/ui/jquery.ui.tooltip.min.js
jquery-ui-widget /wp-includes/js/jquery/ui/jquery.ui.widget.min.js
jquery-form /wp-includes/js/jquery/jquery.form.js
jquery-color /wp-includes/js/jquery/jquery.color.min.js
suggest /wp-includes/js/jquery/suggest.js
schedule /wp-includes/js/jquery/jquery.schedule.js
jquery-query /wp-includes/js/jquery/jquery.query.js
jquery-serialize-object /wp-includes/js/jquery/jquery.serialize-object.js
jquery-hotkeys /wp-includes/js/jquery/jquery.hotkeys.js
jquery-table-hotkeys /wp-includes/js/jquery/jquery.table-hotkeys.js
jquery-touch-punch /wp-includes/js/jquery/jquery.ui.touch-punch.js
jquery-masonry /wp-includes/js/jquery/jquery.masonry.min.js
thickbox /wp-includes/js/thickbox/thickbox.js
jcrop /wp-includes/js/jcrop/jquery.Jcrop.js
swfobject /wp-includes/js/swfobject.js
plupload /wp-includes/js/plupload/plupload.js
plupload-html5 wp-includes/js/plupload/plupload.html5.js
plupload-flash /wp-includes/js/plupload/plupload.flash.js
plupload-silverlight /wp-includes/js/plupload/plupload.silverlight.js
plupload-html4 /wp-includes/js/plupload/plupload.html4.js
plupload-all plupload, plupload-html5, plupload-flash, plupload-silverlight, plupload-html4
plupload-handlers /wp-includes/js/plupload/handlers.js
wp-plupload /wp-includes/js/plupload/wp-plupload.js
swfupload /wp-includes/js/swfupload/swfupload.js
swfupload-swfobject /wp-includes/js/swfupload/plugins/swfupload.swfobject.js
swfupload-queue /wp-includes/js/swfupload/plugins/swfupload.queue.js
swfupload-speed /wp-includes/js/swfupload/plugins/swfupload.speed.js
swfupload-all /wp-includes/js/swfupload/swfupload-all.js
swfupload-handlers /wp-includes/js/swfupload/handlers.js
comment-reply /wp-includes/js/comment-reply.js
json2 /wp-includes/js/json2.js
underscore /wp-includes/js/underscore.min.js
backbone /wp-includes/js/backbone.min.js
wp-util /wp-includes/js/wp-util.js
wp-backbone /wp-includes/js/wp-backbone.js
revisions /wp-admin/js/revisions.js
imgareaselect /wp-includes/js/imgareaselect/jquery.imgareaselect.js
mediaelement /wp-includes/js/mediaelement/mediaelement-and-player.min.js
wp-mediaelement /wp-includes/js/mediaelement/wp-mediaelement.js
zxcvbn-async /wp-includes/js/zxcvbn-async.js
password-strength-meter /wp-admin/js/password-strength-meter.js
user-profile /wp-admin/js/user-profile.js
user-suggest /wp-admin/js/user-suggest.js
admin-bar /wp-includes/js/admin-bar.js
wplink /wp-includes/js/wplink.js
wpdialogs /wp-includes/js/tinymce/plugins/wpdialogs/js/wpdialog.js
wpdialogs-popup /wp-includes/js/tinymce/plugins/wpdialogs/js/popup.js
word-count /wp-admin/js/word-count.js
media-upload /wp-admin/js/media-upload.js
hoverIntent /wp-includes/js/hoverIntent.js
customize-base /wp-includes/js/customize-base.js

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File: wp-includes/functions.wp-scripts.php. View all references

function wp_register_script( $handle, $src, $deps = array(), $ver = false, $args = array() ) {
	if ( ! is_array( $args ) ) {
		$args = array(
			'in_footer' => (bool) $args,
	_wp_scripts_maybe_doing_it_wrong( __FUNCTION__, $handle );

	$wp_scripts = wp_scripts();

	$registered = $wp_scripts->add( $handle, $src, $deps, $ver );
	if ( ! empty( $args['in_footer'] ) ) {
		$wp_scripts->add_data( $handle, 'group', 1 );
	if ( ! empty( $args['strategy'] ) ) {
		$wp_scripts->add_data( $handle, 'strategy', $args['strategy'] );
	return $registered;

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Version Description
6.3.0 The $in_footer parameter of type boolean was overloaded to be an $args parameter of type array.
4.3.0 A return value was added.
2.1.0 Introduced.

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User Contributed Notes

  1. Skip to note 1 content
    Contributed by Peter Ph

    Easy way to link to external JS library and use it easily in project:

     wp_register_script( 'someScript-js', 'https://domain.com/someScript.js' , '', '', true );

    this will put the someScript.js at the bottom of our HTML file before

    wp_enqueue_script( 'someScript-js' );
  2. Skip to note 2 content
    Contributed by tazotodua

    Corrected code from Luizaris:

    add_action("wp_enqueue_scripts", "myscripts");
    function myscripts() { 
                            get_template_directory_uri() .'/myscript.js',   //
                            array ('jquery', 'jquery-ui'),					//depends on these, however, they are registered by core already, so no need to enqueue them.
                            false, false);
  3. Skip to note 3 content
    Contributed by ashishsthanp

    In a case where first script should be loaded only if another second script is loaded:

    function my_enqueue_scripts()
        wp_register_script( 'first', get_template_directory_uri() . 'js/first.js' );
        wp_enqueue_script( 'second', get_template_directory_uri() . 'js/second.js', array( 'first' ) );
    add_action( 'wp_enqueue_scripts', 'my_enqueue_scripts' );

    Here, first.js will load( before second.js ) only if second.js is enqueued/loaded.

  4. Skip to note 4 content
    Contributed by jhned

    Note to moderator: if there’s a better place to report this feedback, please email me at josh@cnpagency.com. I checked WordPress Trac, but it didn’t seem to be the right place for documentation feedback.

    I disagree with this part of the documentation:

    The function should be called using the wp_enqueue_scripts action hook if you want to call it on the front-end of the site. To call it on the administration screens, use the admin_enqueue_scripts action hook. For the login screen, use the login_enqueue_scripts action hook. Calling it outside of an action hook can often lead to unexpected results and should be avoided.

    First off, according to _wp_scripts_maybe_doing_it_wrong, init is also an acceptable hook for registering scripts. The benefit we get from registering scripts on init is that plugins can get a comprehensive list of the registered scripts and styles in the WordPress Admin by accessing the “registered” property of the $wp_scripts and $wp_styles globals. If we’re going to register scripts and styles, we should be able to pull a full list of the registered scripts and styles. The recommended usage is only for code efficiency, and has no other useful aspect to it.

  5. Skip to note 5 content
    Contributed by luizarios

    Using register_script() to add a script and its dependencies

    function myscripts() {
        //get some external script that is needed for this script
        wp_enqueue_script('jquery-ui', 'http://ajax.googleapis.com/ajax/libs/jqueryui/1.9.1/jquery-ui.min.js'); 
        $script = get_template_directory_uri() . '/library/myscript.js';
                            array ('jquery', 'jquery-ui'), 
                            false, false);
        //always enqueue the script after registering or nothing will happen
    add_action("wp_enqueue_scripts", "myscripts");

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