Disable wordpress rest api

functions.php

function disable_json_api () {
  // Filters for WP-API version 1.x
  add_filter('json_enabled', '__return_false');
  add_filter('json_jsonp_enabled', '__return_false');

  // Filters for WP-API version 2.x
  add_filter('rest_enabled', '__return_false');
  add_filter('rest_jsonp_enabled', '__return_false');
}

function remove_json_api () {
    // Remove the REST API lines from the HTML Header
    remove_action( 'wp_head', 'rest_output_link_wp_head', 10 );
    remove_action( 'wp_head', 'wp_oembed_add_discovery_links', 10 );

    // Remove the REST API endpoint.
    remove_action( 'rest_api_init', 'wp_oembed_register_route' );

    // Turn off oEmbed auto discovery.
    add_filter( 'embed_oembed_discover', '__return_false' );

    // Don't filter oEmbed results.
    remove_filter( 'oembed_dataparse', 'wp_filter_oembed_result', 10 );

    // Remove oEmbed discovery links.
    remove_action( 'wp_head', 'wp_oembed_add_discovery_links' );

    // Remove oEmbed-specific JavaScript from the front-end and back-end.
    remove_action( 'wp_head', 'wp_oembed_add_host_js' );

   // Remove all embeds rewrite rules.
   add_filter( 'rewrite_rules_array', 'disable_embeds_rewrites' );

}

add_action( 'after_setup_theme', 'remove_json_api' );
add_action( 'after_setup_theme', 'disable_json_api' );