---
title: "Core Web Vitals (CWV) — monitoring glossary"
description: "Core Web Vitals are a set of three Google-defined metrics that measure real-user experience on a webpage: Largest Contentful Paint (LCP), Interaction to Next…"
canonical: "https://lemwatch.com/glossary/core-web-vitals"
source: "https://lemwatch.com"
---

# Core Web Vitals (CWV)

> Core Web Vitals are a set of three Google-defined metrics that measure real-user experience on a webpage: Largest Contentful Paint (LCP), Interaction to Next Paint (INP), and Cumulative Layout Shift (CLS). They are direct Google ranking signals.

## Definition

 LCP measures loading performance — how long before the largest visible element renders. Good is under 2.5 seconds. INP measures responsiveness — the longest interaction delay during the page session. Good is under 200 ms. CLS measures visual stability — how much page content shifts after first render. Good is under 0.1.

 Core Web Vitals are measured both in the lab (via Lighthouse / PageSpeed Insights) and in the field (via the Chrome User Experience Report — CrUX — which only counts real Chrome users on real devices). Field data is what Google uses for ranking.

## Why it matters

 Core Web Vitals are part of Google's Page Experience ranking algorithm and directly affect organic search position, especially in competitive verticals. They also correlate strongly with conversion rate — every 100 ms of LCP improvement typically lifts revenue by 1-2% on e-commerce sites.

 See it in the product: [Performance monitoring](https://lemwatch.com/features).


## Related

- [Monitoring glossary](https://lemwatch.com/glossary)
- [LCP](https://lemwatch.com/glossary/lcp)
- [CLS](https://lemwatch.com/glossary/cls)
- [INP](https://lemwatch.com/glossary/inp)
- [TTFB](https://lemwatch.com/glossary/ttfb)
- [All monitoring checks](https://lemwatch.com/features)
- [CSP (Content Security Policy)](https://lemwatch.com/glossary/csp)