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Critical CSS Generator

Critical CSS is the CSS required to render the above-the-fold content. By preloading this CSS, before the larger CSS file, your webpage will load faster. This in turns improves customer satisfaction and SEO scores for your website.

This Critical CSS generator reduces render-blocking resources, minimizes bandwidth usage, and ensures faster perceived load times. The result is quicker page rendering and improved performance, vital for retaining visitors and boosting conversions.

The generator is simple to use. You can use it for each of the webpages that you would like to optimize. Once added, your Pagespeed Insight metrics will improve drastically.

Why should I use a Critical CSS Generator?

CSS stylesheets block the rendering of pages. Pages might remain blank until the browser completes requesting, downloading, and parsing all stylesheets. To boost rendering of pages, minimizing the CSS load is crucial.

Manually identifying critical CSS can be laborious. This generator streamlines the process by automating the identification of essential CSS.

From an SEO perspective, quicker page loading times are crucial for search engine rankings. Google's algorithm prioritizes fast-loading websites, considering them more user-friendly. By optimizing Critical CSS, you create a streamlined browsing experience, signaling search engines that your site is responsive and valuable. Improved pagespeed contributes to lower bounce rates, longer user sessions, and ultimately, a positive impact on your SEO efforts.

How do I add the Critical CSS generated to my webpage?

Once you've generated the critical CSS for your page, you can add it to our webpage. See the example below on how to do this. 

<!doctype html>
<html>
  <head>
    <style>
      //put critical css here
    </style>
    </head>
  <body>
    <div class="blue">
      Hello, world!
    </div>
    <noscript id="deferred-styles">
      <link rel="stylesheet" type="text/css" href="main-css-file.css"/>
    </noscript>
    <script>
      var loadDeferredStyles = function() {
        var addStylesNode = document.getElementById("deferred-styles");
        var replacement = document.createElement("div");
        replacement.innerHTML = addStylesNode.textContent;
        document.body.appendChild(replacement)
        addStylesNode.parentElement.removeChild(addStylesNode);
      };
      var raf = window.requestAnimationFrame || window.mozRequestAnimationFrame ||
          window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
      if (raf) raf(function() { window.setTimeout(loadDeferredStyles, 0); });
      else window.addEventListener('load', loadDeferredStyles);
    </script>
  </body>
</html>

In the above example, you would put your critical CSS in the head section of the DOM. The other css files will appear in the body, which means they will be loaded later in the webpage lifecycle.

By loading the critical CSS in the head of the page, all DOM elements located before the large css files will use the critical CSS at the start of the webpage rendering process.

Does this work for mobile websites as well?

If you have a responsive website, generating the critical CSS with our tool will also work on mobile devices. You will notice improved pagespeed scores on mobile devices.

Does this tool remove unused CSS?

It will not remove unused CSS. This tool will check your webpage and see what CSS is required to display the above the fold content of your page. This CSS can be added to the page before the other (larger) CSS file, resulting in faster rendering of your webpages.