Core Web Vitals in Plain Words: Why a Slow Site Costs You Leads

Google measures how a page feels to real visitors with three numbers, called Core Web Vitals. They affect search results a little and visitors a lot: people leave slow pages before they read a word.

The three numbers

LCP (Largest Contentful Paint) is how long it takes until the main part of the page is visible. Good means 2.5 seconds or less.

INP (Interaction to Next Paint) is how quickly the page answers a tap or a click. Good means 200 milliseconds or less. In March 2024 it replaces the older measure, FID, as one of the three.

CLS (Cumulative Layout Shift) is how much the page jumps while it loads. Good means 0.1 or less. You know the feeling: you go to tap a button and it moves.

Where to see your numbers

PageSpeed Insights shows them for any address, free. If the site has enough visitors, it also shows what real people experienced over the last weeks, which matters more than a single test.

The fixes that give the most

For most business sites the list is short.

• Serve images in a modern format and in the size they are shown.
• Give every image and embed a fixed width and height, so nothing jumps.
• Load the first screen first; let videos, maps and chat widgets wait.
• Remove scripts that no longer serve anyone. Old tracking codes are the classic case.
• Use hosting that answers quickly. A cheap server can undo every other effort.

What speed has to do with leads

A fast page is not a prize in itself. It keeps the visitors you already paid to bring, whether through ads or through months of SEO work. When a page is slow, the first thing to fall is the number of enquiries from phones.

We build every site to pass these measures, and check them again after launch. See what goes into our website design and development, or read about the basics a site needs before ads. For a look at your own numbers, write to us.

Questions and answers

Do Core Web Vitals decide my place on Google?

They are one signal among many. Good content for the search still matters most, but between similar pages the faster one has the advantage.

My desktop score is high and my mobile score is low. Which one counts?

Mobile. Most visitors come from phones, and Google looks at the mobile version of the page.