# Core Web Vitals: what do Google's page experience metrics measure?

> Core Web Vitals explained: Google's three page experience metrics, the official good and poor thresholds, a worked example for a service business.

Updated on October 15, 2026 · https://app.pilotiko.com/en/glossary/core-web-vitals

Core Web Vitals are three metrics Google uses to describe real-world page experience: Largest Contentful Paint for loading, Interaction to Next Paint for responsiveness and Cumulative Layout Shift for visual stability. A page meets the bar when each one hits the good threshold at the 75th percentile of visits.

## In short
- LCP covers loading, INP covers responsiveness, CLS covers visual stability.
- Good means LCP of 2.5 s or less, INP of 200 ms or less, CLS of 0.1 or less.
- Read them at the 75th percentile, with mobile and desktop split.
- Google recommends good scores but does not promise rankings for them.

## Where do Core Web Vitals come from?

Web Vitals is a Google initiative documented on web.dev. Out of many possible performance measurements, three are labelled core because they track what a person actually feels: does the main content show up quickly, does the page respond when tapped, and does it stay put while you read [1]?

The set is not frozen. [INP](https://app.pilotiko.com/en/glossary/inp) became a stable Core Web Vital in 2024, taking over from First Input Delay, which only looked at the delay of the very first interaction on a page [1][4].

The other two are [LCP](https://app.pilotiko.com/en/glossary/lcp), which times the biggest visible element, and [CLS](https://app.pilotiko.com/en/glossary/cls), which scores unexpected movement of content.

## What are the official thresholds?

| Metric | What it tracks | Good | Needs improvement | Poor |
|---|---|---|---|---|
| LCP | Render time of the largest visible image, text block or video | 2.5 s or less | over 2.5 s up to 4 s | over 4 s |
| INP | Delay before the screen responds to a click, tap or key press | 200 ms or less | over 200 ms up to 500 ms | over 500 ms |
| CLS | Size of the worst burst of unexpected layout shifts | 0.1 or less | over 0.1 up to 0.25 | over 0.25 |

Sources: web.dev articles on LCP, INP and CLS [3][4][5]. Mobile and desktop are assessed separately.

## Why the 75th percentile?

Web.dev asks site owners to look at the value reached by 75% of page loads, split between mobile and desktop [1]. That means your own test on the office connection matters less than what most real customers see, often on a phone between jobs.

Using a high percentile avoids two traps at once: trusting one lucky test run, and panicking over a handful of extreme visits.

## Do Core Web Vitals affect Google rankings?

Google Search Central strongly recommends good Core Web Vitals and says this lines up with what its core ranking systems seek to reward [2]. It does not say that a good score on its own will lift a page in results.

For a small business, the practical reading is that a slow or jumpy page loses customers before rankings even come into play. Useful content and solid [search engine optimization](https://app.pilotiko.com/en/glossary/seo) still come first.

## What does a quick audit look like for a small business?

**Example: the booking page of an HVAC contractor in Laval**

Assume the Core Web Vitals report in Search Console shows these mobile values for the Book a visit page. The numbers are made up for illustration.

- Mobile LCP (75th percentile) : 3.1 s, needs improvement
- Mobile INP (75th percentile) : 540 ms, poor
- Mobile CLS (75th percentile) : 0.04, good
- Metrics in the green : 1 of 3
- **= Fix responsiveness first: a heavy chat widget and a calendar script block the main thread when visitors pick a time slot.**

## What mistakes do people make with Core Web Vitals?

- Judging a page on a single lab test instead of field data from real visitors.
- Looking at the average rather than the 75th percentile.
- Tuning desktop and forgetting mobile, where many service calls start.
- Still reporting FID, which INP replaced in 2024.
- Piling on tracking, chat and ad scripts without checking what they do to responsiveness.

## Does Pilotiko measure Core Web Vitals?

No, that is not an advertised feature. Pilotiko builds and hosts your business website and generates its [structured data](https://app.pilotiko.com/en/glossary/structured-data), [XML sitemap](https://app.pilotiko.com/en/glossary/xml-sitemap) and [robots.txt](https://app.pilotiko.com/en/glossary/robots-txt) file, but it does not provide a Core Web Vitals dashboard. Use Google Search Console for that.

## Frequently asked questions

### What are the three Core Web Vitals?

LCP measures how fast the main content loads, INP measures how quickly the page responds to interactions and CLS measures how stable the layout is. Together they cover the first things a visitor notices.

### Is FID still a Core Web Vital?

No. INP replaced it in 2024. FID only measured the input delay of the first interaction, while INP looks at every click, tap and key press during the visit.

### Where can I see my site's Core Web Vitals?

Google points to the Core Web Vitals report in Search Console, which shows how your pages perform [2]. Web.dev also has guides to measure, debug and improve each metric.

### Does a 10-page site need to care?

Yes, at least for the pages that lead to a call or a booking. Small sites often have little field data, so check key pages with testing tools while remembering that real-user data is what counts.

### Will a good score bring in more customers?

Not by itself. Good metrics remove friction, but they do not create demand. Your offer, content and reputation still do the heavy lifting.

### Why is my mobile score worse than desktop?

Phones often have less processing power and patchier connections. Since web.dev recommends assessing the two separately, a gap is normal and should be worked on as its own problem.

## Sources

1. web.dev (Google), « Web Vitals », https://web.dev/articles/vitals (accessed on 2026-10-15)
2. Google Search Central, « Understanding Core Web Vitals and Google search results », https://developers.google.com/search/docs/appearance/core-web-vitals (accessed on 2026-10-15)
3. web.dev (Google), « Largest Contentful Paint (LCP) », https://web.dev/articles/lcp (accessed on 2026-10-15)
4. web.dev (Google), « Interaction to Next Paint (INP) », https://web.dev/articles/inp (accessed on 2026-10-15)
5. web.dev (Google), « Cumulative Layout Shift (CLS) », https://web.dev/articles/cls (accessed on 2026-10-15)