Question 1

What are Core Web Vitals?

Accepted Answer

Three metrics Google uses as a ranking signal: Largest Contentful Paint (loading, good is under 2.5s), Interaction to Next Paint (responsiveness, good is under 200ms), and Cumulative Layout Shift (visual stability, good is under 0.1).

Question 2

What is the difference between field and lab data?

Accepted Answer

Field data is real Chrome telemetry from people who actually visited your page in the last 28 days, and it is what Google ranks on. Lab data is one simulated run in a data centre. They can differ enormously — we measured a site with a 16ms lab TTFB against 893ms in the field.

Question 3

Why does my site show no field data?

Accepted Answer

The Chrome UX Report only samples origins with enough traffic. Below that threshold no field data exists, so we fall back to a lab run and label it as such rather than presenting a simulation as real user experience.

Question 4

Why is INP sometimes reported as no data?

Accepted Answer

INP can only be measured from real interactions, so it has no lab equivalent. Rather than substituting Total Blocking Time and calling it INP, we report no data and show TBT separately as the closest proxy.

Question 5

Do Core Web Vitals really affect rankings?

Accepted Answer

Yes, but modestly. Google treats them as a tiebreaker rather than a primary factor — relevance still wins. Fix crawlability and content first, then speed.

Free Core Web Vitals Checker

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Free Core Web Vitals Checker

What you get

Frequently asked questions

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