Defer-youtube-videos

<script type="text/javascript">
    function init() {
        var vidDefer = document.getElementsByTagName('iframe');
        for (var i=0; i<vidDefer.length; i++) {
            if(vidDefer[i].getAttribute('data-src')) {
                vidDefer[i].setAttribute('src',vidDefer[i].getAttribute('data-src'));
            }
        }
    } window.onload = init;
</script>

// The Html
<iframe width="560" height="315" src="" data-src="https://www.youtube.com/embed/fBCAOjAS9d4" frameborder="0" allowfullscreen></iframe>