Remove REST API Links from Header

WordPress adds REST API links (wp-json) to wp_head. If you do not need public API access, remove the links. Add to your functions.php file. For more on securing the REST API.

remove_action( 'wp_head', 'rest_output_link_wp_head' );
remove_action( 'wp_head', 'wp_oembed_add_discovery_links' );
remove_action( 'template_redirect', 'rest_output_link_header', 11 );