By default wordpress now has emoji icons enabled as from wordpress version 4.2.
Although this is a cool feature, if you don’t use them, I would recommend turning them off. The emojicon feature actually loads additional javascript (wp-emoji-release.min.js) within the page which could slow down the loading of your pages – it’s just another additional snippet of javascript that is not necessary if you don’t want them enabled.
I also notice that AVG anti virus professional is alerting every time I visit a wordpress site with them enabled. So far, I beleive this is a false positive, as having scanned the sites, all is reporting clear from virus and malware.
Note: clearing the checkbox in settings – writing (Convert emoticons like :-) and :-P to graphics on display) does not stop the javascript from loading.
How to Disable Emojis in WordPress 4.2
In your functions.php, add the following lines:
// REMOVE WP EMOJI ICONS
remove_action('wp_head', 'print_emoji_detection_script', 7);
remove_action('wp_print_styles', 'print_emoji_styles');
remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
remove_action( 'admin_print_styles', 'print_emoji_styles' );