LCP (Largest Contentful Paint) is a Core Web Vital metric that measures the time it takes for the largest text or image element within the viewport to load. There are several factors that can cause slow LCP, including:
- Slow server response time: Slow server response time can cause delays in the time it takes for the server to process a request and send the response to the client. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- Large image and video files: Large image and video files can slow down the loading of a page, as they take longer to download and render. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- Unoptimized images: Images that are not properly optimized, such as those that are not compressed or scaled, can slow down the loading of a page. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- Slow network: A slow network can cause delays in the time it takes for the browser to download the resources from the server. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- Render-blocking CSS and JavaScript: CSS and JavaScript files that are not properly optimized, such as those that are not minified or deferred, can slow down the rendering of a page. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- Third-party scripts and widgets: Third-party scripts and widgets can slow down the loading of a page, as they often need to download additional resources and perform additional processing. This can result in slower LCP, as it takes longer for the largest text or image element to load.
- High traffic: High traffic can slow down the process of generating and delivering the response, leading to slow LCP, as it takes longer for the largest text or image element to load.
- Server location: if the server is located far away from the client, the network latency can increase the LCP.
- Lazy loading: Lazy loading is a technique that delays the loading of certain images and other resources until they are needed. If a website uses lazy loading, the LCP may be affected if the largest text or image element is not loaded until the user scrolls down the page.
How do fix these factors causing LCP
There are several steps that website owners and developers can take to prevent slow LCP and improve the performance of their website.
- Optimize server response time: Website owners and developers can take steps to optimize server response time by upgrading server resources, optimizing database, optimizing PHP code, optimizing plugins, implementing caching, and scaling.
- Optimize images and videos: Website owners and developers can optimize images and videos by compressing and scaling them, using next-gen image formats like WebP, and using lazy loading.
- Use a Content Delivery Network (CDN): Website owners and developers can use a CDN to reduce the distance that resources need to travel and improve the loading time of the website.
- Reduce the number of third-party scripts and widgets: Website owners and developers can reduce the number of third-party scripts and widgets by only including the ones that are essential to the website and deferring or asynchronously loading the others.
- Optimize CSS and JavaScript: Website owners and developers can optimize CSS and JavaScript by minifying and compressing them, and deferring or asynchronously loading them.
- Use lazy loading: Website owners and developers can use lazy loading to delay the loading of certain images and other resources until they are needed. This can help to improve LCP by ensuring that the largest text or image element is loaded as quickly as possible.
- Use browser caching: Browser caching can be used to store static resources like images, CSS and javascripts in the browser, so that the browser doesn’t have to download them every time the user visits the website, this can help to improve LCP.
- Optimize the critical rendering path: Optimizing the critical rendering path can help to improve LCP by reducing the number of steps the browser needs to take to render the page. This can include reducing the number of elements on the page, minimizing the use of complex CSS selectors, and inlining critical CSS.
- Monitor and measure LCP: Website owners and developers can monitor and measure LCP by using tools such as Google Lighthouse, WebPageTest, and Chrome DevTools. This can help to identify areas of the website that are causing slow LCP, and allow for targeted optimization efforts.
- Optimize the website for mobile devices: Mobile devices often have slower internet connections than desktop computers, so it’s important to make sure that the website is optimized for mobile devices. This can include using responsive design, optimizing images and videos, and reducing the number of elements on the page.
- Use preconnect and preload: Using preconnect and preload can help to improve LCP by allowing the browser to establish a connection to a server and start loading resources before the browser actually requests them.
In summary, there are a number of steps that website owners and developers can take to prevent slow LCP and improve the performance of their website. These include optimizing server response time, optimizing images and videos, using a Content Delivery Network (CDN), reducing the number of third-party scripts and widgets, optimizing CSS and JavaScript, using lazy loading, using browser caching, optimizing the critical rendering path, monitoring and measuring LCP, optimizing the website for mobile devices, and using preconnect and preload. By taking these steps, website owners and developers can improve LCP, resulting in a better user experience and better visibility on search engine.
