Largest Contentful Paint (LCP)

Largest Contentful Paint (LCP) is a Core Web Vital used to evaluate perceived loading performance. It records the rendering time of the largest eligible content element within the viewport during a page load. A large hero image, substantial heading text, or video poster may become the LCP element; the browser determines which candidate counts.

A good LCP is generally 2.5 seconds or less at the 75th percentile of page visits. Values above 2.5 seconds and up to 4 seconds need improvement, while values over 4 seconds are considered poor. This classification is based on an aggregate of real experiences, not on a single screenshot or an isolated desktop lab result.

Slow server response, image discovery delays, oversized media, blocking resources, and late rendering can all affect the metric. Optimization should focus on the actual LCP element and the page's load path rather than blindly compressing every image. Good LCP supports a better visitor experience but does not guarantee search rankings or conversions.