How To Optimize the Largest Contentful Paint (LCP) On Your Website

Thanks to Google, websites in this decade are considering the user experience more and putting in more effort to ensure that every user gets the same smooth experience across all devices. Whether your website is for your eCommerce business or onsite business, a lot goes into making a website’s user experience smooth. On the flip side, any small loophole can make the user experience unpleasant, which can discourage potential customers in addition to getting flagged by Google. However, the largest contentful paint (LCP) is not in any way “small” because the LCP, as a Core Web Vitals metric, accounts for 25% of the performance score of a website. Hence, prioritize your LCP to improve the user experience of your website.

What is the Largest Contentful Paint (LCP)?

The LCP is one of the Core Web Vitals metrics Google created to measure the user experience of a webpage to help determine the overall user experience (UX) of websites. The LCP measures how long it takes for the biggest visual element on a webpage to render on the client-side. The quicker the LCP loads on users’ devices, the better. A high LCP score means the user experience is poor. A business website, eCommerce, or onsite, should aim for an LCP score between 1.2 and 2.5 seconds.

According to Google, these elements impact the largest contentful paint of a website

[img] elements
[image] elements inside an [svg] element
elements (the poster image in use)
Any element with a background image that loads through the url() function instead of a CSS gradient
Block-level elements that contain text nodes or inline-level text elements children

How To Reduce The Largest Contentful Paint Score of Your Website

Start your LCP optimization strategy by reviewing the initial HTML document; check when the LCP resource begins and ends. Secondly, evaluate the LCP resource; use developer tools such as WebPageTest to discover the LCP element of your website. Reviewing your LCP resource will give you insight into how much optimization your LCP needs.

That said, here are three effective ways to optimize your LCP.

Use a Content Delivery Network (CDN)

A CDN can improve your website LCP in numerous ways because of its multiple functions, all of which help increase your website speed and reduce your LCP score. First, you can use a CDN for the static content on your website, such as font files, JS, and CSS, to make their load time faster. You can also use a CDN for dynamic content, such as HTML or APIs, to cache their responses on CDN nodes. However, using a CDN for dynamic content is more complex.

For websites that receive huge traffic loads regularly, a CDN can help you manage your website traffic better. Because you are using a third-party CDN, it will provide additional servers to help manage traffic load when the origin server is struggling. Hence, a CDN can balance the network load by reducing requests in the origin server.

By now, you can tell that the CDN is a tool with many functions. A CDN can also optimize images in real-time when you use an image CDN software. An image CDN can speed up the rendering time of a media-rich website by compressing the images to smaller sizes without reducing their quality. Additionally, an image CDN can make your images more responsive to various devices to ensure that your website meets Google’s mobile-first indexing standard. An image CDN will scale your images for mobile layout. Finally, an image CDN can also speed up the image loading time of your website because the CDN downloads images from the closest server instead of the origin server.

Improve Server Response Time

Here’s a quick math; if your server response time for requests is slow, the render time for your web pages will also be slow, and it will affect your LCP negatively. The interaction between a user’s browser (the client-side) and the server is a factor that affects the page loading speed. The request back-and-forth between them is called the round trip time (RTT), and if it is slow, your LCP score will be high. So, optimize your server response time to improve your LCP.

First, analyze your servers. Evaluate the DB queries, computation, and page construction that happen on your server. Check your incoming server requests to fish out all possible obstructions; the bottlenecks can be anything from a buggy DB query to an inefficient page construction.

Here are some common ways to fix your server response time;

Pre-render your pages: increase the load speed of your server by pre-rendering your web pages. Instead of loading the web page the user’s browser requests in real-time, pre-rendering will make the server show a stored version of the page.

Increase server capacity: your server specifications can and will affect your server response time and overall performance, especially when it starts juggling more load than its original capacity. The simple solution is to increase the server capacity — increase the storage and upgrade the CPU. You may have to switch your server provider to increase your server capacity.

Pre-connect to third-party domains: pre-connecting to third-party domains to send above-the-fold content such as images, CSS, and JS can increase your website loading speed, however, you have to inform the browser to connect to the third-party origins without delay. Indicate by using the rel=”reconnect” attribute of the tag.

Remove Render-blocking Resources

Your LCP score may remain high because your JS and CSS files contain rendering-blocking resources that slow down page loading. Typically, when the browser receives an HTML page from your website server, it will parse the DOM tree. But it will wait for any JS files or external stylesheets in the DOM before concluding the parsing of the rest of the DOM tree. Hence, it will take longer for the page to load.

Reduce the bundles of files you send to the browser. Split some bundles. Inform the browser to continue without waiting for bundles that are not required for the page to load. Use the ‘defer’ attribute in the script tag to inform the browser to continue the DOM parsing and execute the JS file later. You can also minify the JS and CSS files to reduce unnecessary code execution and white spaces.

To summarize, you can optimize your LCP if you

1. Use a Content Delivery Network (CDN)
2. Improve server response time
3. Remove render-blocking resources