How To Defer Iframe
// Move src to data-src <iframe src="" data-src="https://www.youtube.com/embed/JdyDz6quE18"></iframe> // Add this script function deferIframe() { var iframeElem = document.getElementsByTagName('iframe'); for ( var i = 0; i < iframeElem.length; i++ ) { if(iframeElem[i].getAttribute('data-src')) { iframeElem[i].setAttribute('src',iframeElem[i].getAttribute('data-src')); } } } window.onload = deferIframe;