Core Web Vitals sound technical, but they measure three plain, experience-level questions: did the page load fast, did it respond quickly when clicked, and did it stay visually stable while loading? A business owner doesn't need to fix these personally, but understanding them means asking a developer the right questions.
Largest Contentful Paint (LCP) — "did it load fast?"
This measures how long it takes for the main content — usually a large image or block of text — to become visible. A slow LCP often traces back to unoptimised images or a slow hosting server, both fixable without a full rebuild.
Interaction to Next Paint (INP) — "did it respond quickly?"
This measures the delay between a visitor clicking or tapping something and the page actually responding. A sluggish INP is often caused by too much JavaScript running at once — frequently from stacking too many third-party widgets and scripts.
Cumulative Layout Shift (CLS) — "did it stay stable?"
This measures how much content unexpectedly jumps around while a page loads — the frustrating experience of trying to tap a button that shifts the moment before your finger lands. It's usually fixed by reserving proper space for images and ads before they load, rather than letting the layout jump once they appear.
Why this matters beyond the technical score
Google uses these metrics as a ranking factor, but more importantly, poor scores in all three directly correlate with visitors leaving before they convert. Checking a site's scores (freely, via Google's PageSpeed Insights) gives a concrete, non-technical starting point for a conversation with whoever maintains the site.