Since version 4.2 release, WordPress natively adds supports Emoji characters. Because if this WordPress loads some extra java scripts and CSS files in the header.
If you don’t use Emoji and want to remove them, just add the following code snippets to your theme functions.php file.
/**
* Disable the emoji's
*/
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_action( 'init', 'disable_emojis' );