LCP Core Web Vitals Explained: Optimize & Fix LCP Issues | Quattr Blog

LCP Core Web Vitals Explained

What is Largest Contentful Paint (LCP) & Fix LCP Issues At Scale To Provide A Good User Experience

By Colton Miller

LCP Core Web Vitals Explained & Fix LCP Issues

We are still seeing a lot of articles about performance. This is because Google puts a lot of emphasis on user experience and web page performance. Performance is no longer just about page load speeds, but rather how your users feel throughout your website’s journey. 

Since the emphasis is on user experience, Google rolled out the Core Web Vitals algorithm update. This made user experience metrics key ranking factors. Largest Contentful Paint or LCP is one of those metrics. 

Largest Contentful Paint metric measures the loading time of the largest visual element on a website. A significant parameter of Core Web Vitals, it aims to provide a positive user experience.

In this blog, we try to understand LCP as a Core Web Vitals metric and why you should focus on fixing LCP issues. Explore the tools that can help you and steps to optimize LCP scores for your web pages.

What is Largest Contentful Paint (LCP)?

Largest Contentful Paint or LCP is the time it takes to render the first meaningful paint of the page. Meaningful paint means that it is the first paint of the page that is visible to the user. The paint that is visible to the user in the area of the page that is fully loaded and displayed or the above-the-fold content.

Largest Contentful Paint is measured by the amount of time it takes the browser to render the first pixels of a web page.

This is when the browser starts downloading the content on the page, including images, CSS, and other assets, and when it starts painting pixels on the screen.

LCP is one of the Core Web Vitals metrics. Make sure you optimize your web pages for First Input Delay (FID) and Cumulative Layout Shifts (CLS) as well.

What Affects Largest Contentful Paint?

It is important to understand what affects LCP so that you can optimize your web pages for better LCP scores. Largest Contentful Paint or LCP is affected mainly by image loading time and network latency.

  1. Image Slow to Load: The time it takes to load images is critical for LCP. If the images take longer to load, then your page will take longer to render the first pixels. 

  2. Network Latency: LCP is also affected by network latency as it is related to the speed of the internet connection.

Largest Contentful Paint v/s Other Rendering Metrics

Largest Contentful Paint is a rendering measure that records the exact instant that a certain area of a web page is drawn in the user's browser. While Google chooses to incorporate LCP in its ranking algorithm, there are additional rendering metrics you may improve for your website:

  1. First Contentful Paint marks the time between the start of the loading process and the rendering of any part of the page's content

  2. First Meaningful Paint shows when the essential content is rendered

  3. DOMContentLoaded fires when the initial HTML has been fully loaded and parsed. The difference between DCL and load is that external resources like pictures don’t need to be loaded for the DCL to occur.

  4. Load Event fires when the whole page has been loaded, including all dependent resources such as stylesheets and images.

While all of these measures can be helpful for optimizing your site, they aren't the ideal alternatives for measuring how quickly the major content of a page loads and becomes accessible to consumers.

Why is LCP Important?

The purpose of the Largest Contentful Paint metric is to provide a positive user experience. LCP lets users know that the page has started loading so they don’t have to wait till the entire page is rendered. 

You can use LCP to fix critical website issues and provide a better user experience.

Fixing these issues can help improve LCP scores and your SEO ranking as well. For search engines like Google, providing the best user experience is key. Metrics like LCP help you provide a fast-loading web page to your target users which in return boosts your SEO rankings and efforts. 

While Google still focuses on content in its ranking algorithms, providing a better user experience is also crucial. Largest Contentful Paint will play a critical role in ranking websites & thus you should optimize Core Web Vitals for the top spot on search engines.

What is a Good LCP Score?

Largest Contentful Paint is a metric that is represented by a time. Higher the time, slower the page load.

According to Google, LCP should occur within 2.5 seconds of the first time the page loads. Any value greater than 4 seconds is considered poor.

LCP Core Web Vitals metrics
LCP Core Web Vitals Metrics

It is essential to constantly monitor this metric in order to keep load times below 2.5 seconds. In the case of a negative variation, resulting in an increase in time, the cause must be investigated and action taken.

Tools that can Help Measure LCP

You can measure LCP in two ways:

  1. Directly on the site. (field test)

  2. Or through performance simulations performed by algorithms. (lab test)

Various tools speed up the work and make measurements more accurate for each of these methods. All of the tools suggested below are free and can help measure LCP scores for your web pages. 

Field method tools to help measure LCP

  1. Chrome User Experience Report (CrUX) data represents the web experience of real-world Chrome users and can be accessed via API. Using this method allows developers and webmasters to gain insight into how users are experiencing the pages. Based on the same you can improve each Core Web Vitals metric and fix any LCP issues identified.

  2. Page Speed Insights (PSI) can help you find out which element is the largest on your page. The “Diagnostics” section shows you which element triggers the LCP metric.

  3. Search Console (Core Web Vitals report) is based on real-world user data. It displays a chart for both mobile and desktop platforms that indicates how many pages are good, need improvement, and poor in page experience scores.

You may open each report to get a comprehensive list of URLs and their scores. You may check the specifics of how each statistic rates after picking a URL. You may then navigate to PageSpeed Insights to get ideas for improvements.

Lab tools to help measure LCP

  1. Chrome DevTools: Just go to the page you want to test an LCP score for. Then right-click to open the “Inspect” panel, find “Performance”, and refresh the page. After reloading, you will see all the metrics in action on the page. The recording will show both the First Contentful Paint and Largest Contentful Paint.

  2. Lighthouse analyzes the web performance of a page and generates a report containing metrics and suggestions for improving them. As for LCP, you will see its score and suggestions for improvement, as well as which elements you can improve.

  3. WebPageTest is a free web-based tool that measures LCP. It uses the lab method to simulate different scenarios and record their results. It offers more detailed information about the page like DOMContentLoaded, time spent on each object, and total time spent loading the page. This can help further optimize your site for speed.

LCP is a Google-created statistic, we can readily discover it in all of these tools. It enables the use of a Largest Contentful Paint test as necessary, as well as ongoing monitoring of the results.

How to Optimize Web Pages for LCP & Fix LCP Issues?

If your LCP scores are low, then you must take measures to fix the issues. Low LCP scores can have an impact on your traffic and your conversion rates. 

Bad LCP scores can be caused due to an issue on your server or an issue with the elements on your page. The first stage is to discover which LCP candidate causes the final largest-contentious-paint entry and determines your LCP score. The kind of element determines how you should start with optimizing your LCP.

1. Fix Above the Fold Elements If your images are taking longer to load, then you must optimize your image sizes and image placement. Sufficient compression should place you in the "good" LCP category. When it comes to text, make sure it's in the first HTML response the browser receives from your server.

2. Fix page layout issues If you feel that your page layout is affecting your LCP, then you should revisit your page layout. Opt for page layouts that are not too load-heavy and can be optimized for faster loading.

3. Server Optimization Several reasons can cause the server speed to slow down and result in a poor LCP score. You can do one of the following things to optimize server issues.

  1. You can move your website to a new host. Finding a server close to where the majority of your users are located can help. This will reduce the server response time and ensure fast-loading web pages.

  2. Use a CDN (Content Delivery Network), and host your assets on multiple servers across the globe. This way you are able to deliver content sooner to users anywhere in the world.

4. Enable Caching Your server may be required to make third-party connections, which might have a detrimental influence on your LCP score, especially if they are required to show critical information. Caching can assist in caching copies of assets after they have been downloaded once so that they do not need to be downloaded each time the browser requests them.

5. Optimize render-blocking resources Render blocking resources like CSS and Javascript assets delay parsing the initial HTML and hence lower LCP scores. Thus it is essential to optimize the render-blocking resources.

  1. Defer non-critical JS scripts so that the browser may parse the HTML and create the DOM before loading and executing JS. You may also inline your JS in the HTML to avoid rendering delays and to start it as soon as the page loads as feasible.

  2. Your crucial CSS code must load as soon as feasible. One thing you can do to help your CSS load faster is to inline it in the HTML. If the CSS is too huge, you may trim its size such that it is less than the LCP element.

Last but not the least, keep track of your LCP scores over time. This will help you understand where you can improve and how you can improve.

Improve User Experience & LCP Core Web Vitals with Quattr

The current process of optimizing web pages for LCP only allows you to optimize the scores for one web page at a time. This can be a challenge if you have a website with thousands of web pages. Existing tools do not allow you to optimize and track your LCP across your entire website.

The Quattr platform addresses the shortcomings of the current process and helps you optimize your site to improve overall page experience and LCP Scores. You can use Quattr to view LCP scores for each page of your website all at once and filter pages based on whether the LCP score is Good, Needs Improvement, or Poor. Quattr also lets you compare LCP, and other Core Web Vital scores against your competitors in one view. 

Quattr platform allows you to compare Core Web Vitals against your competitors. Check LCP, FID, and CLS scores for competitors and evaluate overall Page Experience.
Compare Core Web Vitals against your competitors in Quattr

With Quattr, you can scale and optimize render-blocking resources for multiple pages. The Usability Recommendations dashboard in Quattr gives you a list of prioritized recommendations and performance improvements you can make across your entire site.

Compare key performance and usability issues across webpages in Quattr
Usability Recommendations by the Quattr Platform

This list is ranked based on what key pages you should focus on and aligns optimization efforts with business metrics like clicks and conversions so that you can measure the benefits of your efforts.

Summary

LCP is a great metric to understand how well your page is performing. It can help you understand how fast your website loads and how well it performs on different devices. The above guide helps you understand what affects LCP and how to fix LCP issues. 

While the current optimization tools allow you to improve LCP scores on a page level, you can scale your efforts with Quattr. 

You may also want to check out our guide on how to improve Core Web Vitals metrics and how to improve website page speed.

Optimize Scores & Fix LCP Issues with Quattr today!

About the Author

Colton Miller is the Sr. SEO Success Manager at Quattr. He has 12 years of experience in selling, servicing, supporting, and strategizing SEO. He has dealt with thousands of sites across hundreds of verticals and has also helped create and define scaled solutions for hundreds of thousands of SMBs and enterprise clients alike. Colton writes about SEO, search engine insights, and algorithm updates. He is always available for questions or comments on Twitter @BigCSEO feel free to connect!

About Quattr

Quattr is an innovative and fast-growing venture-backed company based in Palo Alto, California USA. We are a Delaware corporation that has raised over $7M in venture capital. Quattr's AI-first platform evaluates like search engines to find opportunities across content, experience, and discoverability. A team of growth concierge analyze your data and recommends the top improvements to make for faster organic traffic growth. Growth-driven brands trust Quattr and are seeing sustained traffic growth.