WordPress at a glance

has_filter() WP 1.0

Check if any filter has been registered for a hook.

When using the $function_to_check argument, this function may return a non-boolean value that evaluates to false (e.g. 0), so use the === operator for testing the return value.

Basis of: has_action()
1 time — 0.000043 sec (very fast) | 50000 times — 0.91 sec (very fast) | PHP 7.0.2, WP 4.4.2

No Hooks.


true|false|Int. If $function_to_check is omitted, returns boolean for whether the hook has anything registered. When checking a specific function, the priority of that hook is returned, or false if the function is not attached.


has_filter( $tag, $function_to_check );
$tag(string) (required)
The name of the filter hook.
The callback to check for.
Default: false


  • Global. WP_Hook[]. $wp_filter Stores all of the filters and actions.


Since 2.5.0 Introduced.

Code of has_filter() WP 5.7.1

function has_filter( $tag, $function_to_check = false ) {
	global $wp_filter;

	if ( ! isset( $wp_filter[ $tag ] ) ) {
		return false;

	return $wp_filter[ $tag ]->has_filter( $tag, $function_to_check );

From tag: Filters (hooks)

More from category: Hooks (actions, filters)

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