WordPress at a glance
filter is not described

emoji_url filter-hook . WP 4.2.0

Filters the URL where emoji png images are hosted.

Usage

add_filter( 'emoji_url', 'filter_function_name_1006' );
function filter_function_name_1006( $url ){
	// filter...

	return $url;
}
$url(string)
The emoji base URL for png images.

Where the hook is called

_print_emoji_detection_script()
wp_staticize_emoji()
wp-includes/formatting.php 5037
'baseUrl' => apply_filters( 'emoji_url', 'https://s.w.org/images/core/emoji/11/72x72/' ),
wp-includes/formatting.php 5177
$cdn_url = apply_filters( 'emoji_url', 'https://s.w.org/images/core/emoji/11/72x72/' );

Where the hook is used (in WP core)

Does not used.