title: "Load" event on script with async and/or defer
body: <p>When embedding scripts like:</p>
  
  <pre><code>&lt;script src="..." async defer&gt;&lt;/script&gt;
  </code></pre>
  
  <p>Is there a way to know when they're finished loading?</p>
  
  <p>Usually when the <code>window.load</code> event is called, one would expect all scripts to be ready as well. But I don't know if that still holds when you load them with <code>async</code> or <code>defer</code>. I've read some docs online but couldn't find anything conclusive on this issue.</p>