Full Definition
Core Web Vitals are a set of specific, measurable metrics Google uses to assess the real-world user experience of a web page. Google made them official ranking signals in 2021. There are three:
**LCP (Largest Contentful Paint)**: How long does it take for the main visible content — usually a hero image or headline — to load? Target: under 2.5 seconds.
**INP (Interaction to Next Paint)**: How quickly does the page respond when you click or tap something? Target: under 200 milliseconds.
**CLS (Cumulative Layout Shift)**: Does the page content jump around while loading — causing you to accidentally click the wrong thing? Target: below 0.1.
Why do these matter beyond rankings? Because they directly mirror user experience. A page with terrible CLS that makes users tap wrong buttons will have a higher bounce rate, fewer conversions, and frustrated visitors — all of which ultimately hurt your business regardless of rankings.
For most business websites built on WordPress or similar platforms, the biggest CWV issues are: unoptimised images (killing LCP), layout shifts from fonts or ads loading late (CLS), and heavy JavaScript frameworks (INP).
Actionable tip: Go to PageSpeed Insights (pagespeed.web.dev), enter your homepage URL, and check the 'Field Data' section — that shows real user experience data Google is actually using, not just a lab simulation.