What is LCP? Impact and how to optimize website performance

What is LCP? Impact and how to optimize website performance Picture 1

In June 2021, Google will rank websites through the Core Web Vitals index. In which, LCP is considered one of the important indicators related to page loading speed. So what is LCP? How does it affect and how to optimize the website effectively?  TipsMake will  help you find out these questions in the article below!

What is LCP?

LCP stands for Largest Contentful Paint. This is a metric used to measure the time it takes to load the largest piece of content on a website. This content can be video, image or text. LCP tells you what users have received when accessing your website.

On the other hand, LCP is also an indispensable part of Core Web Vitals - a factor that Google uses as a ranking signal to promote web developers or SEOer indexes more effectively and friendly. Web Vitals will include FID, LCP, CLS. The presence of these 3 indexes will be related to the user experience when accessing your website.

The Important Role of Largest Contentful Paint for Websites

For websites, Largest Contentful Paint has the following roles:

Directly affects user experience

When users visit a website, they expect the page to load quickly and display the main content they are interested in as soon as possible. LCP measures the time from when a user starts loading a page until the main content is fully displayed on the screen.

If the LCP is high, it means that users have to wait a long time to see the main content, leading to an unsatisfactory experience. Conversely, a low LCP will make users feel that the website is more responsive and trustworthy.

Helps increase page loading speed

Fast page load speeds  help users access content quickly and seamlessly, keeping them on the page longer and exploring more content.

LCP optimization techniques like minimizing server response times, compressing images, and optimizing resources all contribute to faster loading of a website. A fast loading website is more engaging for users, helping to keep them on the site longer and improving engagement rates.

Reduce bounce rate

When users have to wait too long to see the main content on a website, they tend to leave and move on to another website. This not only loses the opportunity to interact with users but also negatively affects the bounce rate of the website.

By improving LCP, that is, reducing the time it takes for the main content to appear, your website's bounce rate will decrease significantly. Users will tend to stay on the page longer, increasing their engagement and exploring more content on the website.

Increase conversion rate

In e-commerce, page load speed is an important factor that directly affects users' purchasing decisions. When a website loads quickly and displays the main content immediately, users are more likely to take actions such as making a purchase, registering, or filling out information.

On the other hand, if the LCP is high, users may feel frustrated and leave the site before completing a transaction. This leads to lost sales opportunities and reduced revenue. Therefore, optimizing LCP is an important step to increase conversion rates and achieve business goals.

SEO friendly and improves SERP rankings

Google has confirmed that website performance, including LCP, is an important factor in their search ranking algorithm. A website with a good LCP not only provides a better user experience but is also SEO friendly, helping to improve rankings on search results pages.

When a website has a good LCP, Google will appreciate that website and tend to rank higher in search results. This not only helps increase organic traffic from search but also enhances the website's reputation and trustworthiness to users.

What is a good LCP score?

A good LCP score is determined by the time it takes for the main content of a web page to be displayed. According to Google's guidelines, a good LCP score should be under 2.5 seconds. Here are the specific thresholds recommended by Google:

● Good - LCP under 2.5 seconds: This is the ideal level that every website should aim for. When LCP is in this range, users will have a good experience because the main content of the website is displayed quickly and completely.

● Needs improvement - LCP between 2.5 seconds and 4 seconds: In this range, while the site is not too slow, it still needs further optimization to ensure users don't have to wait too long to see the main content. Sites in this range may see a decrease in engagement and an increase in bounce rate if not improved.

● Poor - LCP over 4 seconds: This is a red flag that requires immediate attention. When LCP exceeds 4 seconds, users tend to leave the page before the main content is displayed, resulting in a very poor user experience. It also negatively affects the website's ranking on search engines like Google.

Factors affecting LCP score

Causes that affect the LCP score are often related to:

Slow server response time

If the server does not respond quickly, the web page content will be delayed. To improve LCP, it is necessary to ensure the server is fast and stable, minimizing response time by using techniques such as data compression and database optimization.

Render-blocking JavaScript and CSS

When the browser has to download and execute JavaScript and CSS files before displaying the content, the display time of the main content is delayed. To overcome this, you can defer the loading of unnecessary files, compress files, and use asynchronous loading techniques.

Slow resource load time

Slow loading times for resources, such as large images or other media files, also affect LCP scores. To improve, optimize image sizes, use efficient image formats, and load resources intelligently, such as loading images only when needed.

Client Elements

Client-side factors, such as the user's browser and device, also affect LCP. Different browsers can handle resources differently, and less powerful devices will take longer to load and display content. To minimize this impact, optimize your website to work well across a variety of devices and browsers.

How to Improve Largest Contentful Paint Score Effectively

To improve your Largest Contentful Paint score, you need to apply some of the following methods:

Image Optimization

Images are often the largest element on a web page, so optimizing them is a good first step. Use the right image format like WebP, JPG, or PNG at the optimal size. Additionally, compress images before uploading to reduce the size without sacrificing quality. It's What is LCP? Impact and how to optimize website performance Picture 2 also a good idea to use the srcset attribute in the tag to provide different image sizes for different devices.

Optimize fonts

Fonts can also affect page load times. Use system fonts or compress font files to reduce their size. Avoid using too many different font styles and sizes, this will not only reduce load times but also create consistency on your website.

Minimize the size of JavaScript, CSS, HTML files

Minifying JavaScript, CSS, and HTML files by removing unnecessary whitespace, comments, and code can reduce file size and speed up page load times. Using automated tools to do this can save you time and effort.

Remove JavaScript, CSS blocking rendering

Consider removing or delaying loading of unnecessary code until the main content has been rendered. This can help reduce LCP load times and improve user experience.

Defer non-critical CSS

To improve your LCP score, you can defer loading non-critical CSS until the page has loaded. Use the media attribute for unnecessary CSS files to defer them and load them only when needed. This will reduce the initial render time of the page.

Use Preloading for Critical Resources

Preloading is a technique that preloads important resources such as images, fonts, and CSS files. Designating important resources to be preloaded reduces the time it takes for them to render, thereby improving LCP score.

Enable Page Caching

Page Caching temporarily stores web pages so that users don't have to reload the entire page each time they visit. By enabling caching, you can reduce page load times for users who have visited before, improving their experience and LCP score.

Upgrade your current Web Hosting service

The quality of your web hosting service can have a big impact on your page load speed. If you are using a slow hosting service, consider upgrading to a better service, especially VPS or Dedicated Server packages. This will not only improve your loading time but also increase the stability of your website.

Use CDN

A content delivery network helps distribute content from multiple locations around the world, minimizing page load latency. By using  a CDN , you can improve page load speeds for users in multiple locations, thereby improving your LCP score.

Reduce client-side rendering time

Client-side rendering times can impact LCP. Optimize your JavaScript to minimize heavy tasks, use Web Workers to handle complex tasks, and ensure that pages render quickly on the user's device.

Some tools to help measure LCP index effectively

To measure the LCP index, the following tools will be available:

Google PageSpeed ​​Insight

This tool provides detailed analysis of page load speed, including LCP, and offers suggestions for improvement. To measure the main metric, simply enter the URL of the website and see the results.

Google LightHouse

Lighthouse is an open source tool that helps you check your website performance, including metrics like LCP, FCP, and CLS. It provides detailed reports and optimization suggestions.

Popular SEO tools

In addition to PageSpeed ​​Insights and Lighthouse, you can also use popular SEO tools like Ahrefs, SEMrush, or Moz to monitor your website performance. These tools provide information about page load speed and help you identify problems that need to be fixed.

It can be seen that LCP is a very important index for website performance. Through the above article, we hope you have understood the meaning of this index and have an effective plan to improve your website to achieve the highest expectations.

Micah Soto

Update 12 February 2025