gistfile1.txt

<?php
/**
 * Plugin Name: Disable Embeds posts for me
 * Description: Don't want to fetch external emebed posts?
 * Version:     1.0
 * Author:      Julio Potier
 * Author URI:  https://wp-rocket.me
 * License:     GPLv2+
 *
 */

add_filter( 'embed_oembed_html', 'hack_embed_oembed_html', 10, 2 );
function hack_embed_oembed_html( $html, $url ) {
	if ( ! class_exists( 'WP_oEmbed' ) ) {
		include( ABSPATH . WPINC . '/class-oembed.php' );
	}
	$WP_oEmbed = new WP_oEmbed();
	if ( ! $WP_oEmbed->get_provider( $url, array( 'discover' => false ) ) ) {
		return '';
	}
	return $html;
}