Core Web Vitals are the three numbers Google uses to judge your site’s real-world experience — and they influence both rankings and, more importantly, whether visitors stay. Here is what each one measures, in plain language, with the single highest-impact WordPress fix for each.
LCP: how fast the main thing appears
Largest Contentful Paint measures when the biggest visible element — usually a hero image or headline — finishes rendering. Good is under 2.5 seconds. Highest-impact WordPress fix: full-page caching, plus preloading the hero image so the browser fetches it immediately.
INP: how fast the page responds when touched
Interaction to Next Paint measures the lag between a tap or click and the screen visibly responding, across the whole visit. Good is under 200 milliseconds. Highest-impact fix: delay third-party scripts (chat, analytics, pixels) until the visitor actually interacts — they are almost always the main-thread hogs.
CLS: how much the page jumps around
Cumulative Layout Shift measures unexpected movement — the button that dodges your thumb because an ad loaded above it. Good is under 0.1. Highest-impact fix: explicit width and height attributes on every image and reserved space for embeds and ads.
Measure in the field, not the lab
Lab tools like Lighthouse are diagnostics; the scores that count come from real Chrome users via the CrUX dataset. Check Search Console’s Core Web Vitals report monthly — it reflects what Google actually sees.