What are Core Web Vitals?
Core Web Vitals are Google's three measures of how a page feels to real visitors. Largest Contentful Paint times how fast the main content appears, Interaction to Next Paint times how quickly a tap gets a response, and Cumulative Layout Shift measures jumping. Good means 2.5 seconds, 200 milliseconds and 0.1 or less.
The short version
- Core Web Vitals are three numbers Google uses to describe how a page feels to use.
- LCP: how long the main content takes to show. Good is 2.5 seconds or less.
- INP: how quickly the page reacts to a tap or click. Good is 200 milliseconds or less.
- CLS: how much the layout jumps while loading. Good is 0.1 or less.
- They’re measured on real Chrome visits, so phones count as much as your office computer.
What does each measure mean?
Picture a customer opening your services page on a phone in a parking lot. Three things shape how that feels, and each Core Web Vital tracks one of them.
Largest Contentful Paint (LCP) is the moment the biggest thing on screen appears. Usually that’s the main photo or the headline. Until then, the page feels blank.
Interaction to Next Paint (INP) is how long the page takes to react after someone taps a button, opens a menu or types in a form. A slow reaction makes people tap twice or give up. It replaced an older measure, First Input Delay, in 2024.
Cumulative Layout Shift (CLS) adds up the times content moves while it loads. It’s what makes you tap the wrong link because a banner pushed everything down.
Google’s Web Vitals guide on web.dev sets the “good” marks at 2.5 seconds for LCP, 200 milliseconds for INP and 0.1 for CLS. A page passes when the 75th percentile of visits meets each mark, measured separately for phones and desktops.
Why do they matter?
They describe what your visitors actually live through. A page that loads its main photo slowly or jumps around costs you calls and form fills, whatever your ranking.
Google also uses them as part of its page experience signals. They won’t lift weak content to the top, but a frustrating page doesn’t help.
What usually fixes each one?
- Slow LCP: a huge hero image is the usual cause. Resize and compress it (see how big images should be), use caching and decent hosting, and don’t make the main image wait on a slider.
- Slow INP: too much JavaScript running at once. Chat widgets, tracking tags, heavy page builders and stacks of plugins are common sources. See how many plugins is too many.
- High CLS: images, embeds and ads with no space reserved for them, and fonts or cookie banners that push content as they load. Give each one a fixed size.
What are the common mistakes?
- Testing only on a fast office computer. Your numbers come from real visitors, many on phones and mobile data.
- Treating the PageSpeed score as the vitals. The score is a lab test; the vitals come from real visits. Our answer on whether a low PageSpeed score matters explains the difference.
- Expecting instant results. Field data covers the last 28 days, so a fix takes a few weeks to show fully.
What if your site has no Core Web Vitals data?
Small sites often don’t get enough Chrome visits for Google to report field data. That’s normal. Use the lab results in PageSpeed Insights as a checklist, and check Search Console’s report again as traffic grows.
How much does it cost, and how long does it take?
Checking is free in PageSpeed Insights and Search Console. Fixes range from minutes (compressing one image) to a rebuild for a heavy theme. Allow about a month after a fix for real-visitor data to catch up.
How does E-3 handle this?
Fixes made in E-3’s speed program are tested on a staging copy first. Our free speed test shows your own numbers in plain English.
Related questions
Common questions
- Where can I see my Core Web Vitals?
- Search Console's Core Web Vitals report shows them for real visitors across your site. PageSpeed Insights shows them for a single page when Chrome has enough visit data.
- Do Core Web Vitals decide my Google ranking?
- They're part of Google's page experience signals, but helpful content matters more. A slow, jumpy page still loses visitors whatever it does for ranking.
- What replaced First Input Delay?
- Interaction to Next Paint (INP) replaced First Input Delay as a Core Web Vital in 2024. INP looks at how fast the page responds to taps and clicks across the whole visit.
Rather talk it through?
Call our team, or send a note and we’ll reply within one business day. No pressure and no jargon.