Core Web Vitals explained for people who are not developers

Core Web Vitals are three measurements Google uses to judge how good your page feels to a real visitor. They are part of how Google ranks pages, and they line up closely with whether people stay on your site, so they matter for both search traffic and conversions.

Largest Contentful Paint (LCP)

This measures how long it takes for the main content to appear. If your hero image or headline takes four seconds to show up, visitors are already losing patience. Aim for under two and a half seconds. Large unoptimised images are the most common cause of a slow LCP.

Cumulative Layout Shift (CLS)

This measures how much the page jumps around as it loads. If a button moves just as someone goes to tap it, that is layout shift, and it is deeply frustrating. Reserving space for images and adverts usually fixes it. Aim for a score under 0.1.

Interaction to Next Paint (INP)

This measures how quickly the page responds when someone taps or clicks. Heavy scripts that block the browser make the page feel sluggish. Keeping JavaScript lean keeps interactions snappy.

What to do about it

You do not need to memorise the numbers. Compress your images and serve them in a modern format, avoid loading everything at once, and keep scripts to what you need. A report that measures your Core Web Vitals on both mobile and desktop will tell you which of the three is holding you back so you can fix the right thing.