What Is LCP? How to Improve Largest Contentful Paint
Learn what Largest Contentful Paint means, what affects LCP, how to diagnose slow LCP, and practical ways to improve it.
What Is Largest Contentful Paint?
Largest Contentful Paint (LCP) measures how quickly the largest visible content element is rendered in the viewport. It is one of Google's Core Web Vitals and is commonly affected by server response time, images, CSS, fonts, and client-side rendering.
What Can Become the LCP Element?
Depending on the page, the LCP element can be a large image, a video poster image, a heading, or another large block of content.
Common Causes of Slow LCP
Slow Server Response
If the server takes too long to return the initial HTML, the browser has to wait before it can start rendering the page.
Unoptimized Hero Images
Large hero images are a common source of LCP delays. Use appropriately sized responsive images and modern formats such as WebP or AVIF where suitable.
Render-Blocking Resources
Large CSS files and synchronous scripts can delay rendering. Reduce unnecessary resources and avoid loading non-critical code before the main content.
Font Delays
Web fonts can affect when important text becomes visible. Use efficient font loading strategies and avoid unnecessary font variants.
How to Improve LCP
- Improve server response time.
- Optimize the LCP image or content.
- Preload only truly critical resources.
- Reduce render-blocking CSS.
- Remove unnecessary JavaScript.
- Use caching and a CDN where appropriate.
- Monitor LCP after deployments.
For the bigger picture, read our Core Web Vitals guide and speed optimization guide.
Conclusion
LCP is not solved by one optimization. Diagnose which part of the loading path is delaying the main content, fix the largest bottleneck, and continue monitoring the page as it changes.