Suspendisse in justo eu magna luctus suscipit. Nunc feugiat mi a tellus consequat imperdiet. Sed lacinia, urna non tincidunt mattis, tortor neque adipiscing diam, a cursus ipsum ante quis turpis. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos. Nulla metus metus, ullamcorper vel, tincidunt sed, euismod in, nibh. Fusce ac turpis quis ligula lacinia aliquet. Morbi lectus risus, iaculis vel, suscipit quis, luctus non, massa. Proin ut ligula vel nunc egestas porttitor. Nulla quis sem at nibh elementum imperdiet. Lorem ipsum dolor sit amet, consectetur adipiscing elit. We then load the rest of the CSS using the method you described: Ībove the fold - all required styles inlinedīelow the fold, all classes in external style sheet There are only three CSS classes required to make this hero section work so we inline the CSS for it. Just to make this clear, let's assume we have a website with a simple hero section that appears above the fold. The reference to the stylesheet inside of a noscript element works as a fallback for browsers that don't execute JavaScript."nulling" the onload handler once it is used helps some browsers avoid re-calling the handler upon switching the rel attribute.The onload attribute in the link allows the CSS to be processed when it finishes loading.
You can learn more about preload in the Preload critical assets guide.
link rel="preload" as="style" requests the stylesheet asynchronously.Use the method you showed within your original question:.Remove the critical CSS from your style sheet - there is no point downloading it twice!.Now that you have inlined the critical CSS you only have two steps left: This massively helps your First Contentful Paint, Largest Contentful Paint (normally) etc. Once you inline all the styles the browser has everything it needs to render the page without another network request. This goes back to the part I was saying in the introduction. This just means that you minify it and then add it to your site inside a tag at the top of the page. Once you have identified the critical CSS you simply inline it. It can be laborious if you haven't designed the site with this in mind but is worth it. Inspect them on a page with the external CSS included and copy the styles across. Unfortunately I have yet to see a tool that is 100% effective at this so I would suggest you use a tool to grab most of the styles and then (after inlining the critical CSS - see below) remove all external style sheets and see if there are things that do not render correctly. The tool should then export these styles for you. In principle though you are looking for a tool that will map the HTML that is above the fold to the CSS classes and styles that match those items. There are numerous ways you can do this but they often depend on your build process, stack etc. The principle is simple, however it can be quite difficult to get right and may take a bit of patience. What we instead want to do is provide all of the styles required to render the above the fold content immediately so that no further network requests are required. Those extra network requests for the CSS can really slow the page down if someone has a high latency connection (4G for example where the round trip time to the server can be 300ms and higher). Once the styles are downloaded the content can be rendered.
Look to see what styles are required to render the above the fold content.If you have your styles in an external style sheet the browser has to do the following:
However this answer is focused on CSS (the principles are the same, just the methods are different). If your site happens to be rendered with JS then you also need to employ a similar technique as I describe below for the JS required to hydrate / render the initial page content. "Above the fold" is essentially any content that is visible on the screen without scrolling.Ĭritical CSS is all of the CSS required to render the above the fold content. When a browser requests your page it needs the HTML and CSS for any content that appears "above the fold" before it can render it correctly. Understanding what a "render blocking resource" is.
0 kommentar(er)
