Core Web Vitals: what to measure and how to improve each metric

Google has used real user experience as a ranking signal for years. Those signals are the Core Web Vitals, and they boil down to three numbers.

The three metrics that matter

Metric	What it measures	Target
LCP	How long the main content takes to appear	< 2.5 s
INP	How long the page takes to respond to a click	< 200 ms
CLS	How much the content shifts while loading	< 0.1

How to improve LCP

LCP is usually a large image or the main heading. The highest-impact fixes:

• Serve images in WebP or AVIF, at the right size.
• Mark the main image with fetchpriority="high" and load it early.
• Cut the CSS and JavaScript that blocks the first render.
• Use a CDN and cache static assets properly.

How to improve INP

INP measures whether the page reacts quickly when the user interacts. Most of the time the culprit is too much JavaScript:

1. Remove scripts you do not use.
2. Load the rest with defer or lazy loading.
3. Avoid long tasks that block the main thread.
4. Fewer third-party dependencies.

How to improve CLS

CLS shows up when something moves right as you are about to tap it. The fix is reserving space for every element:

• Explicit width and height on images and videos.
• Reserved space for banners, notices and ads.
• Watch out for web fonts: use font-display: swap and fallback metrics.

Measure with real data, not just your laptop

A test on your own machine with a good connection always looks fine. What counts is field data — your real users — which you can see in Search Console.

Rule of thumb: measure first, change one thing, then measure again. Optimizing blindly is the fastest way to waste time.

If you would rather not wrestle with this, we run the audit and apply the fixes.