Largest Contentful Paint (LCP): what it is and how we speed it up

Largest Contentful Paint, or LCP, is how long it takes the biggest thing on your page to show up. That's usually your main photo or headline. Google wants it under 2.5 seconds.

You'll see LCP when you test a site in Google's PageSpeed Insights. It's one of Google's Core Web Vitals. Those are the scores Google uses to judge how fast and stable a page feels.

Why it matters

Google says good Core Web Vitals line up with what its ranking systems reward. So speed can help you show up in search, though good content still comes first.

The bigger reason is people. A slow page loses visitors before they see anything. Google's own data from 2016 found that 53% of mobile visits ended when a page took longer than 3 seconds to load.

What slows LCP down

Most slow LCP scores come down to four things. Here's each one and what we do about it:

• Big images. A huge main photo is the most common cause. We shrink it and serve it in newer formats like WebP or AVIF, which are much smaller.
• Fonts. Custom fonts can hide your text until they finish downloading. We use a setting called font-display: swap so your text shows up right away.
• A slow server. If the server takes a second to answer, nothing else can start. We host sites on a network that serves each page from a location near the visitor.
• Too much JavaScript. Extra scripts, like chat widgets and trackers, can hold up the page. We load anything you don't need right away after the main content.

We also tell the browser to grab the main image first, before it would find it on its own.

One common mistake is lazy loading the main image. Lazy loading means an image waits until you scroll near it. That's great for photos further down the page, but it makes the top photo show up later.

What this means for you

Every site we build has to score 95 or higher on Google Lighthouse's performance test at launch. If it doesn't, we fix it before we hand it over. On our Care plan, we keep checking speed and send you a report each month.

Curious how your current site scores? Get in touch and I'll run the test for you.