What is Largest Contentful Paint (LCP)?

Largest Contentful Paint is a web performance metric that measures the loading performance of a website or web application. It is the time from when the page starts loading to when the largest content element is rendered on the screen.

LCP is a crucial metric for web designers and an integral part of understanding your website performance; it is intended to measure loading performance from the user's perspective, and it's an important metric because it measures when the page's main content is visible to the user. A fast LCP score can make users perceive a web page is loading quickly, while a slow score can lead to prematurely leaving the site. A good LCP score should be under 2.5 seconds.

To improve the performance of your website and the resulting user experience, it is important to understand the impact that LCP can have on the user experience of a website.

  • A slow LCP score can indicate the main page content needs to load more quickly, which can lead to users leaving the site prematurely. This can result in a high bounce rate, negatively impacting the website's search engine ranking and overall visibility. Slow load times can also frustrate users, especially those on slow internet connections or low-end devices. A slow LCP can negatively impact conversion rates, as users may need to stick around longer to complete a desired action.

  • A fast LCP score can make users perceive the website loading quickly, leading to better engagement, conversion rates, and user satisfaction. A good LCP score should be under 2.5 seconds; anything above that may be considered slow and result in a poor user experience.

    It's worth noting that LCP is not the only metric that determines the performance of a website, other metrics, such as First Contentful Paint, Speed Index, Time to Interactive, and Total Blocking Time, also play a crucial role in determining the overall performance of a website and user experience.

So, what can you do to improve LCP and the user experience on your website? Here are several steps you can take to improve Largest Contentful Paint (LCP) on your website:

  • Optimize images: Optimizing images, such as compressing and resizing them, can help reduce the time it takes to load and improve LCP.
  • Minimize the use of large third-party scripts: Large third-party scripts can slow down page loading and negatively impact LCP. Minimizing their use or loading them asynchronously can help improve LCP.
  • Use a Content Delivery Network: A Content Delivery Network (CDN) can speed up the delivery of your website's content to users by caching it on servers closer to the user.
  • Use code splitting: Code splitting is a technique that allows you to split your JavaScript code into smaller chunks that can be loaded on demand. This can help reduce the time it takes for the initial JavaScript to load and improve LCP.
  • Use browser caching: Browser caching allows a browser to store a copy of your website's resources on the user's device so that they don't have to be downloaded again on subsequent visits. This can help reduce the time it takes for the resources to load and improve LCP.
  • Minimize the use of heavy web fonts: Heavy web fonts can slow down page loading and negatively impact LCP. Minimizing heavy web fonts or loading web font techniques such as the font-display CSS property can help improve LCP.
  • Monitor and measure your LCP score: Use browser developer tools or web-based LCP testing tools to monitor and measure your LCP score, and identify areas where improvements can be made.
  • Defer loading of non-critical resources: Defer non-critical resource loading such as analytics, social media widgets, or ads, until the main page content is loaded and visible to the user.

It's worth noting that improving LCP is an ongoing process, and you should regularly monitor your website's performance and adapt your optimization strategies accordingly. As with any optimization, it's essential to test your website/web app in different browsers and devices, as LCP can be affected by other factors.