What Are Core Web Vitals and Why Do They Matter?

Core Web Vitals are a set of metrics Google uses to measure the real-world experience of using your website — essentially, how fast, stable and responsive it feels. They’re a ranking factor, so they’re worth understanding.

Here’s a simple explanation and why they matter.

What they measure

In plain terms, Core Web Vitals measure how quickly your main content loads, how quickly the page responds to interaction, and how stable it is as it loads (does content jump around?). Together they capture how good — or frustrating — your site feels to use.

They’re Google’s attempt to measure real user experience.

Why they matter

Google uses them as a ranking signal, so a site that passes has an edge over one that doesn’t. More importantly, the same things that pass Core Web Vitals — fast loading, no annoying layout shifts — also keep visitors happy and converting.

Passing them helps both your rankings and your conversions.

How to pass them

The usual culprits for failing are slow loading, oversized images, bloated code and unstable layouts. Optimising images and code, good hosting and clean build practices fix most issues. A speed audit shows exactly where you stand.

We build sites that pass Core Web Vitals and can fix ones that don’t.

Practical fixes for each Core Web Vital

Largest Contentful Paint (LCP) is most commonly improved by compressing and preloading the hero image, upgrading to faster hosting, and eliminating render-blocking scripts. Cumulative Layout Shift (CLS) is usually caused by images and embeds without fixed dimensions, or by late-loading fonts that shift text. Adding explicit width and height attributes to images eliminates most CLS issues.

Interaction to Next Paint (INP) — the newest metric — measures how quickly the page responds to clicks and taps. Heavy JavaScript bundles are the usual cause of poor INP scores. Code splitting, deferring non-critical scripts and removing unused plugins all improve it. We test every site against all three metrics before launch and fix anything in the amber or red range.