WP-Mix

Developing WordPress plugins, it’s super useful to know if another specific plugin is active. Fortunately WordPress makes it easy to do, read on to learn how..

To check if a plugin is active, we can use is_plugin_active(). There are two ways to use this function, depending on whether you’re in the Admin Area or on the front-end (i.e., via theme template).

Check in Admin Area

If you’re running in the WP Admin Area, you can use the function as-is, for example:

if (is_plugin_active('plugin-directory/plugin-file.php')) { 
	// plugin is active
}

Note that the parameter accepted by is_plugin_active() is required and must include both the plugin subdirectory and the name of the main plugin file.

Check on front-end

As explained in the WP Codex:

is_plugin_active() is defined in /wp-admin/includes/plugin.php, so this is only available from within the admin pages, and any references to this function must be hooked to admin_init or a later action. If you want to use this function from within a template, you will need to manually require plugin.php.

So with that in mind, here is an example of using the function to check if a plugin is active when on the frontend:

include_once(ABSPATH .'wp-admin/includes/plugin.php');

if (is_plugin_active('plugin-directory/plugin-file.php')) { 
	// plugin is active
}

The function returns either true or false depending on whether or not the specified plugin is active.

References

• WP Codex: is_plugin_active()