Optimizing the WordPress Head Tag Section

11/30/19, Updated: 09/03/22

The initial WordPress head tag section is a bit bloated. There are some quick optimizations via the functions.php file that will improve a WordPress site’s loading time and increase security. The key elements the method below addresses:

• Remove Query Strings from Static Resources – This can improve caching and fix some speed test warnings – Note that this can break how some external resources load (ex: enqueuing a Google Fonts CSS link)

• Header Cleanup – This removes all the unnecessary tags: RSD link, WordPress version number (increasing site’s security), wlwmanifest link, shortlink, and extra feed links (primary RSS feed still functions correctly)

• Disable the Emojis – This removes the emoji support WordPress has built-in for older browsers that isn’t needed for modern browsers

// Remove query strings from static resources 
function _remove_script_version( $src ) {
	$parts = explode( '?', $src );
	return $parts[0];
}
add_filter( 'script_loader_src', '_remove_script_version', 15, 1 );
add_filter( 'style_loader_src', '_remove_script_version', 15, 1 );

// Header cleanup 
add_action( 'do_feed_rss2_comments', 'disable_feeds', -1 );
add_action( 'do_feed_atom_comments', 'disable_feeds', -1 );
add_action( 'feed_links_show_comments_feed', '__return_false', -1 );
remove_action( 'wp_head', 'feed_links_extra', 3 );
remove_action( 'wp_head', 'rsd_link' );
remove_action( 'wp_head', 'wp_generator' );
remove_action( 'wp_head', 'wlwmanifest_link' );
remove_action( 'wp_head', 'wp_shortlink_wp_head', 10, 0 );

// Disable the emojis 
function disable_emojis() {
	remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
	remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
	remove_action( 'wp_print_styles', 'print_emoji_styles' );
	remove_action( 'admin_print_styles', 'print_emoji_styles' ); 
	remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
	remove_filter( 'comment_text_rss', 'wp_staticize_emoji' ); 
	remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
	add_filter( 'tiny_mce_plugins', 'disable_emojis_tinymce' );
	add_filter( 'wp_resource_hints', 'disable_emojis_remove_dns_prefetch', 10, 2 );
}
add_action( 'init', 'disable_emojis' );
function disable_emojis_tinymce( $plugins ) {
	if ( is_array( $plugins ) ) {
		return array_diff( $plugins, array( 'wpemoji' ) );
	} else {
		return array();
	}
}
function disable_emojis_remove_dns_prefetch( $urls, $relation_type ) {
	if ( 'dns-prefetch' == $relation_type ) {
		$emoji_svg_url = apply_filters( 'emoji_svg_url', 'https://s.w.org/images/core/emoji/2/svg/' );
		$urls = array_diff( $urls, array( $emoji_svg_url ) );
	}
	return $urls;
}