Largest Contentful Paint (LCP)

Largest Contentful Paint (LCP) is the metric that allows you to measure the loading time of the largest visual element of a site.

To measure a page's LCP right now, use the free Core Web Vitals Checker.

Considered one of the most significant parameters of Core Web Vitals, Largest Contentful Paint (LCP) measures perceived load speed or how quickly the main content of a web page loads and is visible to users.

What is Largest Contentful Paint (LCP)?

Largest Contentful Paint (LCP) metric reports the render time of the largest image or text block visible within the viewport, relative to when the page first started loading.

Google considers an LCP of 2.5 seconds or less good, measured at the 75th percentile of page loads. See the Core Web Vitals thresholds.

Type of content considered:

Images, including images inside SVG.
Video thumbnails (poster images).
Background images with CSS.
Text elements, such as paragraphs, headings, and lists.

How to improve Largest Contentful Paint (LCP)?

Largest Contentful Paint (LCP) is primarily affected by four factors:

Slow server response times
Render-blocking JavaScript and CSS
Resource load times
Client-side rendering

See what delayed LCP on your result

The Performance diagnostics section of a page speed result shows the Largest Contentful Paint element of that run, and the LCP breakdown splits its time into four phases:

Time to first byte: the server response
Resource load delay: the wait before the LCP image starts downloading
Resource load time: the download itself
Element render delay: the time between the download finishing and the element appearing

The longest phase is where to start. A long load delay, for example, often means the image is discovered late; you can test a preload with a page speed experiment before you deploy it. The same section also lists the Elements that shifted and the CPU time by script.

To get notified when LCP gets worse, create an alert on Largest Contentful Paint.

Every panel on a result, including the LCP breakdown, is explained in Reading a Page Speed result.