A simple method to stop YouTube, Vimeo, and HTML5 videos from playing.

stop-video.js

/**
 * Stop all iframes or HTML5 <video>'s from playing
 */
var stopVideos = function () {
	var videos = document.querySelectorAll('iframe, video');
	Array.prototype.forEach.call(videos, function (video) {
		if (video.tagName.toLowerCase() === 'video') {
			video.pause();
		} else {
			var src = video.src;
			video.src = src;
		}
	});
};