Skip to main content

Confirm

Are you sure?

URLpipe
Sign inStart free

URLpipe

Glossary

Largest Contentful Paint (LCP)

The moment a visitor sees the thing they came for.

By · Last updated: September 2026

TL;DR

Largest Contentful Paint (LCP) is the time from when a page starts loading to when the largest image or text block visible in the viewport has rendered. It is the Core Web Vital for loading speed: 2.5 seconds or less is good, over 4 seconds is poor.

Start freeSee the API

Free plan, no credit card. 1,000 credits a month.

How it works

What counts as the largest element

As the page loads, the browser reports each new largest element in the viewport: an <img>, an image inside an <svg>, a <video>'s poster, an element with a CSS background-image, or a block of text. The last one reported before the visitor interacts is the LCP element, and its render time is the LCP. On most pages it is the hero image or the main heading.

LCP breaks into four parts, and the fix depends on which is large:

  1. 1
    Time to First Byte — the server's response.
  2. 2
    Resource load delay — how long before the browser starts fetching the LCP image.
  3. 3
    Resource load duration — how long the image takes to download.
  4. 4
    Element render delay — the wait between the image arriving and it being painted.

In practice

A common example

A hero image marked loading="lazy", or set as a CSS background, is discovered late: the browser doesn't know it needs it until layout, so load delay dominates. The fix is to make it an ordinary <img>, never lazy-load it, and add fetchpriority="high". A client-rendered hero is worse still: nothing can start until the JavaScript has run.

An LCP image the browser finds early
<img src="/hero.webp" width="1200" height="600" fetchpriority="high" alt="">

URLpipe

Measuring LCP with URLpipe

/lighthouse returns largest-contentful-paint in metrics, in milliseconds, with its 0–1 score. It carries 25% of the Lighthouse 13 performance score. The default mobile run throttles the CPU and network, so expect a higher LCP than on your laptop. include_audits: "true" adds the diagnostics that name the LCP element and its breakdown.

Try it

Largest Contentful Paint (LCP), on a page you choose

Run a Lighthouse audit on any URL

Paste a link and get a real Google Lighthouse audit — performance, accessibility, best practices and SEO scores, plus Core Web Vitals — measured against the live page.

Try it free

Related terms

Core Web VitalsTime to First Byte (TTFB)Speed IndexCumulative Layout Shift (CLS)

FAQ

Frequently asked questions

What is a good LCP score?
2.5 seconds or less at the 75th percentile of page loads. Between 2.5 and 4 seconds needs improvement; over 4 seconds is poor.
What is the LCP element?
The largest image or text block visible in the viewport when the page finishes rendering it. Lighthouse's audit details name it.
Why is my LCP worse on mobile?
Mobile runs simulate a slower CPU and network, and phones often get a different, heavier hero. Lighthouse's mobile preset is deliberately pessimistic.

Keep reading

Run a Lighthouse audit in PHPRun a Lighthouse audit on any URLBest Lighthouse APIsRun a Lighthouse audit in Node.jsReading a Lighthouse auditTotal Blocking Time (TBT)All of glossary

See it on your own pages.

Free plan, no card. Confirm your email and your API key is live — you'll be making real requests in minutes.

Start freeEmail the team