Load Google Ads after entire page has loaded

Try this article.

The trick is to put your ad initializing and loading logic in window's onload event:

<script>
   window.onload = function(){
       ...
   };
</script>

This is my ultimate Vanilla JS solution:

<script async defer src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js"></script>
<script>
    (adsbygoogle = window.adsbygoogle || []).onload = function () {
        [].forEach.call(document.getElementsByClassName('adsbygoogle'), function () {
            adsbygoogle.push({})
        })
    }
</script>