How to Improve and Optimize LCP

Among all Core Web Vital metrics, sites have the most difficulty improving their LCP. Increasing at a slower pace than other metrics, LCP is an important tool to improve user experience, but it comes at a timely cost. Not that tech savvy? Don’t worry, we’ll break it down for you so that you can improve your website and therefore improve your customers’ experiences the easy way.

In this article, we’ll cover:

1. What is LCP
2. How to Improve LCP
3. Core Web Vitals
4. And much more

What is LCP?

What is LCP and how is it utilized in a website?

LCP or “Largest Contentful Paint” is a metric of how long it takes for the main content of a web page to load and how easily visible it is to users. Depending on how long it takes from the initial search of the web page to the first largest image or text block to render, LCP is a metric used by marketers, competitors, and company owners to gauge their website’s reliability.

LCP Broken Down

Within LCP, there are subparts that make up the time it takes for a page to load. These all impact your LCP score. 

1. TTFB or time to first bite relates to the time it takes for the first bite of the HTML document to load after the first click onto that page.

2. Resource load delay is the time between the TTFB and the LCP. Depending on the resources needed to load the LCP, your LCP may be 0.

3. Resource load time relates to the time it takes for your LCP to load its extra resources. Again, this could be 0.

4. Element render delay is the time between when your LCP resources finish loading to when they actually appear on the screen for the reader. 

What is a Good LCP?

Largest Contentful Paint of 2.5 seconds or less is a good LCP, but you do not want to strive for anything lower than 4.0 seconds for at least 75% of page visits. In this case, less is more.

What Causes a Poor LCP Score?

A poor LCP can result in poor user experience and therefore, lesser user experience. Slow server and loading response times can create lag as well as website content that is rendered directly in the browser (client-side rendering), and codes in web files that hinder a web page or prevent it from loading.

How to Improve LCP

In order to improve LCP, improving overall user experience instead of targeting certain users will create the best experience for the most visitors.

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Reduce resource load delay time

By eliminating resource load delay time, which is the first part of your website loading process, is crucial to improving your LCP because it is the first loading time from when a user clicks on your page to when the first HTML document loads. Adding priority hints, minimizing network contention, and using same-origin resources will result in a lower resource load delay time, and therefore, a lower LCP score. 

Reduce element render delay

As an owner of a website, you would want to reduce or eliminate any delays that can hinder your LCP resource from the time your page has finished loading. By removing render-blocking stylesheets or Javascript and using font-display, this reduces overall LCP score. 

Reduce resource load time

Optimizing images and web fonts will reduce long load times while still keeping quality at its peak. Reducing image sizing and utilizing a CDN or Content delivery networks which improve a LCP by helping origin servers load especially during times of high traffic will keep quality high while reducing load time. CDNs utilize additional servers geographically closer to your users to deliver website information to visitors in a timely manner to improve user experience. Be aware that decreasing your image sizes will only decrease your resource loading time. This will then make your element render delay longer, but will ultimately not decrease your LCP score.

Reduce time to first bite

Web developers have the least amount of control over time to first bite because it is the hardest to optimize or decrease. Again, utilizing CDNs will decrease initial load times of the first HTML document which affect all loading times thus after.

Core Web Vitals

Measuring a website’s metrics is an important tool to gauge user experience in three major areas: loading longevity, interactivity, and visual stability. A good LCP loading interface creates a better visitor experience, but what other metrics can affect the reliability of a website?

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Loading Performance

A high or low LCP score influences the time it takes for documents to load after the initial page click. Your website LCP should range between 0 and 2.5 seconds. To improve LCP, see above.

Interactivity

FID or First Input Delay measures the interactivity of a web page. From the initial click of a widget, image, chart, etc. to the response time of the browser to begin processing event handlers affects visitor utilization and interactivity. You should shoot for a FID of 100 milliseconds or less of at least 75% of your visitors. To improve your FID score, breaking up long tasks in JavaScript and using a web worker can make it easier to develop a successfully interactive website.

Visual Stability

CLS or Cumulative Layout Shift measures the visual stability of a website. This is the layout shift score for every unexpected layout shift that happens during the lifespan of a page. Ultimately, any time a visible element of your website shifts in position or size, affects the position of the content surrounding it. You should aim for a maximum of 5 seconds for the window duration of an image. Improving CLS, identifying key issues surrounding your visuals and measuring the elements in the field that impact your CLS score.

Measuring Core Web Vitals

Understanding the issues surrounding your website’s success and visitor metrics and applying relevant changes to your site can do wonders for your website. But only time will tell if your applications are actually helping or potentially harming your website.

Chrome User Experience Report

This analytics site collects measurements for all Core Web Vitals for a quick and easy way to access your website’s performance comparative to other websites.

PageSpeed Insights

PageSpeed Insights is a free analytics tool you can use to analyze the performance of your website while also suggesting recommendations for improvement.

Search Console

Measuring Core Web Vitals Reports, Search Console is a free Google tool to help website developers understand their site’s performance and errors that may hinder it.

Wrapping it Up

Understanding LCP and applying it to your website can seem complex and timely. By ensuring that all four sub parts of your LCP are optimized, your overall LCP score will decrease drastically, resulting in a quick and reliable website for a great customer experience.