Web Performance Glossary

Core Web Vitals

What are Core Web Vitals?

Core Web Vitals are Google's three user-experience metrics for loading, responsiveness, and visual stability: LCP, INP, and CLS.

Plain-English version

Google's main page experience metrics: LCP, INP, and CLS.

Target

All three passing

CWV thresholds

Use thresholds as a triage tool. Field data matters most when there is enough real Chrome traffic for the page.

Target

All three passing

For Core Web Vitals, all three visitor-facing metrics need to pass: LCP, INP, and CLS.

Why it matters

What a visitor feels when CWV is bad.

Why CWV matters

Core Web Vitals matter because they describe whether real visitors can load, use, and trust the page. They can also influence search visibility as part of Google's page experience systems.

What a poor result usually means

Failing Core Web Vitals means at least one important part of the visitor experience is poor. The right fix depends on which metric fails and whether the problem appears in real Chrome field data, lab diagnostics, or both.

What to fix first

Do not chase the score. Fix the bottleneck.

The right fix depends on the metric, the page template, and whether the issue appears in real visitor data.

  1. Start with the failing metric instead of chasing the overall score.
  2. Use field data when enough real visitor data exists.
  3. Use Lighthouse diagnostics to identify likely causes.
  4. Fix one high-impact issue, then compare before and after data.
  5. Monitor continuously because themes, plugins, scripts, and content change.

How nimo helps

Ask nimo: “How do Core Web Vitals affect my search ranking?”

nimo combines CrUX field data, Lighthouse diagnostics, monitoring, and AI explanations so Core Web Vitals become a prioritized fix list instead of a confusing scorecard.

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No signup needed. Takes about 30 seconds.

Related metrics

LCP

Largest Contentful Paint

When the biggest visible element on the page finishes loading.

INP

Interaction to Next Paint

How quickly the page responds to taps and clicks.

CLS

Cumulative Layout Shift

How much content jumps around during loading.

TTFB

Time to First Byte

How long the server takes to start responding.