Core Web Vitals explained simply
By The AsasWeb team 1 min read
Core Web Vitals are the three numbers Google uses to measure how a page feels to a real person. Largest Contentful Paint should be under 2.5 seconds, Cumulative Layout Shift under 0.1, and Interaction to Next Paint under 200 milliseconds. The usual fixes are lighter images, less JavaScript, tuned web fonts, and reserved space for anything that loads late, all measured on a mid-range phone rather than a fast laptop.
Core Web Vitals are three numbers Google uses to describe how your site feels to a real person. They are worth understanding, because they affect both your search ranking and your conversion rate. Here they are without the jargon.
Largest Contentful Paint: does it load quickly?
LCP measures how long the main content takes to appear. Aim for under 2.5 seconds, and for a fast site closer to 2. The usual fixes are lighter images in modern formats, fewer render-blocking resources, and tuned web fonts so the big headline or image shows sooner.
Cumulative Layout Shift: does it stay still?
CLS measures how much the page jumps around while it loads. Nothing is more annoying than tapping a button that moves at the last moment. Aim for under 0.1. The fixes are setting width and height on images, reserving space for anything that loads late, and tuning fonts so text does not reflow when the web font arrives.
Interaction to Next Paint: does it respond?
INP measures how quickly the page reacts when you tap or type. Aim for under 200 milliseconds. The main cause of poor INP is too much JavaScript blocking the main thread, so the cure is usually to ship less of it.
Measure where your users are
The numbers that matter are the ones from a mid-range phone on a real connection, not a fast laptop on office wi-fi. We measure there, because that is where most visitors actually are.
Good vitals are the result of building carefully, not a last-minute patch. If your scores need work, start a project and we will measure them honestly and bring them up.