Your page is slow to appear

Applies to

every page

Typical severity

medium

Effect on conversions

medium

Effort to fix

Quick to fix

What to look for

Largest Contentful Paint over 2.5s on a simulated mid-range phone on 4G (home page), or over 1.2s on a fast connection (other pages).

Why it matters

Largest Contentful Paint measures how long it takes for the biggest piece of content in the first screen to appear. That is usually the hero image, a large heading or a video poster. It is the moment the page feels loaded to a visitor.

While people wait, they see a blank or half-built page. The longer that lasts, the more of them go back to the search results. LCP is one of Google's Core Web Vitals, which form part of how Google assesses page experience.

What good looks like

Google rates LCP of 2.5 seconds or less as good. We measure LCP in a lab test, on a fast connection with no throttling, and flag the page when it is over 2.5 seconds. Over 4 seconds is marked as high severity. Because our test is on a fast connection, real visitors on phones and mobile data will usually see slower times than we report.

How to check it yourself

1. Go to PageSpeed Insights (pagespeed.web.dev) and enter your page address.
2. If your site has enough traffic, the top section shows real-visitor LCP from Chrome users. This is the most reliable number.
3. The lab section below shows LCP on a simulated mid-range phone, and names the LCP element under the diagnostics.
4. In Chrome developer tools, the Performance panel shows LCP live as you reload, and highlights which element it is.
5. Test your key pages separately. Product and article pages often differ from the home page.

How to fix it

• Find the LCP element first. Usually it is the hero image.
• Resize the image to the size it is actually shown at, and compress it. Serve WebP or AVIF where you can.
• Don't lazy-load the hero image. Load it straight away with fetchpriority="high".
• Avoid loading the hero with JavaScript, a slider or a background image set late by a script.
• Reduce render-blocking CSS and scripts in the head, and remove third-party tags you no longer use.
• Use a good host and a CDN so the first response arrives quickly.

<!-- Hero image: sized, modern format, loaded first -->
<img
  src="/hero-1200.avif"
  srcset="/hero-800.avif 800w, /hero-1200.avif 1200w"
  sizes="100vw"
  width="1200" height="600"
  fetchpriority="high"
  alt="Engineer servicing a boiler">

Common mistakes

• Adding loading="lazy" to the hero image.
• Uploading a 4000px photo straight from a camera.
• Using an auto-playing slider as the hero.
• Judging speed only on your own fast office broadband.

AgoraScan measures this automatically on every page it audits, on desktop and mobile.

Based on

• Google Core Web Vitals