If you’ve ever run your site through a speed test, you’ve probably seen three unfamiliar terms near the top of the report: LCP, INP, and CLS. Those are Google’s Core Web Vitals, and they’re the part of “site speed” that Google actually measures and factors into search. They sound technical, but each one maps to something a visitor can feel.
If your site just feels slow and you’re not sure why, these three numbers are a good place to start looking.
LCP: how fast the main content appears
Largest Contentful Paint measures how long it takes for the biggest visible element usually a hero image or a large heading to finish loading. It’s the closest thing to “when does the page feel loaded?” A slow LCP is most often caused by oversized images, slow hosting, or too many scripts loading before the page can show anything. We cover the hosting side in more detail in our post on choosing a domain and hosting.
INP: how quickly the page responds
Interaction to Next Paint measures the delay between a visitor doing something tapping a menu, clicking a button and the page visibly responding. A page can look fully loaded and still feel sticky if heavy scripts are tying up the browser. This is a common side effect of stacking several plugins that each add their own JavaScript.
CLS: whether the page jumps around
Cumulative Layout Shift measures unexpected movement you go to tap a button and the page shifts just as you tap, so you hit something else. It’s usually caused by images without set dimensions, late-loading ads or embeds, or fonts swapping in after the text has already appeared. It’s one of the most annoying issues for visitors and often one of the easiest to fix.
Why this matters for search
Core Web Vitals are one of several signals Google uses to judge page experience. They won’t make weak content rank, but between two similar pages, the one that loads and responds better has an edge. It’s one piece of the basics we list in our SEO basics for WordPress site owners.
How to check your own numbers
Free tools like Google’s PageSpeed Insights and the Core Web Vitals report in Search Console show your real scores and point to the specific causes. Run your homepage and your most important inner page, and look at mobile results first that’s where most sites score worst.
What we’d do about poor scores
The fixes are usually specific, not mysterious: compress and resize images, set dimensions on media, trim unused plugins, add proper caching, and move off weak hosting where needed. That’s the core of our performance optimization service. And because scores drift as a site changes, keeping them healthy is a natural part of a maintenance plan.
If you’d like us to look at your actual numbers, that’s an easy thing to start with on a discovery call.
“Core Web Vitals aren’t abstract scores each one is something a visitor feels.”
