Add/Remove MIME Types in WordPress

This technique could be used if you’re finding that the allowed MIME types list in your WordPress settings aren’t all being adhered to for some reason. It works for WordPress Multisite too, as long as you add this to your parent theme’s functions file, assuming you want it to take effect across all of your sites.

The example code below can be used to add additional MIME types (and/or remove them) via your site’s theme’s functions file. In this example, we add the doc file type (for Microsoft Word doc files) and remove exe (executable) file types. This affects what can and can’t be uploaded to the website via the media manager.

/* Add/remove additional mime types for media library */
function edit_mime_types($mimes){
	
	//add mime types
	$mimes['doc']  = 'application/msword'; 
	
	//remove mime types
	unset( $mimes['exe'] );
	
	return $mimes;
}
add_filter( 'upload_mimes', 'edit_mime_types' );