title: PageSpeed Insights : Load css files after the closing </html>
body: <p><a href="https://developers.google.com/speed/pagespeed/insights/" rel="noreferrer">Google Page insight</a> tells us to optimize CSS file like this :</p>
  
  <blockquote>
    <p>Vous pouvez alors incorporer le code CSS essentiel comme ceci :</p>
  </blockquote>
  
  <pre><code>&lt;html&gt;
    &lt;head&gt;
      &lt;style&gt;
        .blue{color:blue;}
      &lt;/style&gt;
      &lt;/head&gt;
    &lt;body&gt;
      &lt;div class="blue"&gt;
        Hello, world!
      &lt;/div&gt;
    &lt;/body&gt;
  &lt;/html&gt;
  &lt;link rel="stylesheet" href="small.css"&gt;
  </code></pre>
  
  <p>source : <a href="https://developers.google.com/speed/docs/insights/OptimizeCSSDelivery" rel="noreferrer">https://developers.google.com/speed/docs/insights/OptimizeCSSDelivery</a></p>
  
  <p><img src="https://i.stack.imgur.com/cxX39.png" alt="enter image description here"></p>
  
  <p>The French link is <a href="https://developers.google.com/speed/docs/insights/OptimizeCSSDelivery?hl=fr" rel="noreferrer">https://developers.google.com/speed/docs/insights/OptimizeCSSDelivery?hl=fr</a></p>
  
  <p>I’ve never seen such a thing : Integrate css files after the closing <code>&lt;/html&gt;</code> tag.</p>
  
  <p>I’t’s not only in the documentation. It also modify the result of PageSpeed Insights score. I have 100% if i insert css file at the end.</p>
  
  <p>Is it valid HTML ?</p>