An Intro to Core Web Vitals

Core Web Vitals are a small set of metrics Google uses to measure the things that actually matter to the people visiting your website: how fast it loads, how quickly it responds, and how stable it feels while it's loading. They're part of Google's ranking signals, so a site that scores well has an edge in search — and, more importantly, keeps the visitors it worked hard to earn.

The three Core Web Vitals in 2026

There are three. If you read an older guide you'll see "First Input Delay (FID)" listed here — that metric was retired in March 2024 and replaced by Interaction to Next Paint (INP). The current three are:

• Largest Contentful Paint (LCP) — how long it takes for the biggest piece of content on the screen (usually a hero image or headline) to appear. It answers "how fast does this page look loaded?"
• Interaction to Next Paint (INP) — how quickly the page responds when someone taps or clicks. It answers "does this page feel snappy or sluggish?" INP watches every interaction on the page, not just the first one.
• Cumulative Layout Shift (CLS) — how much the layout jumps around as the page loads. It answers "did the button move just as I went to tap it?"

What counts as "good"

Google publishes target thresholds. To pass, you want roughly:

These are measured on real visits (field data), not just a lab test, and Google scores you at the 75th percentile — so a fast result for most people isn't enough if a meaningful slice of your audience has a slow experience.

Why they matter

The link to user experience is direct: a fast LCP, responsive INP, and stable CLS make a site feel quick and trustworthy. A slow, jumpy site makes people leave — and on a business website, leaving means a lost enquiry or sale. Google uses these numbers as one input into ranking precisely because they correlate with whether visitors stick around.

How to improve them

Most of the wins come down to a few things:

• Faster hosting and server-level caching so the page starts arriving sooner (helps LCP). The metric that measures this is Time to First Byte.
• Optimised images — right-sized, modern formats, lazy-loaded below the fold (helps LCP).
• Fewer and lighter scripts, especially third-party ones, so the browser isn't busy when a visitor tries to interact (helps INP).
• Reserved space for images, ads, and embeds so nothing shifts as it loads (helps CLS).

A lot of this is hosting and configuration work rather than something you edit in your content — which is exactly the part a managed host should be handling for you, so you can focus on the business instead of the metrics.