Core Web Vitals are Google’s three measures of how a page feels to real visitors: Largest Contentful Paint (how quickly the main content appears; good is 2.5 seconds or less), Interaction to Next Paint (how quickly the page responds to taps and clicks; good is 200 milliseconds or less) and Cumulative Layout Shift (how much the page jumps around while loading; good is 0.1 or less). Google uses them as one part of its page experience signals.
The three measures
Each measure covers a different part of the experience:
- Largest Contentful Paint (LCP): how long until the biggest piece of content, usually a headline or main image, appears.
- Interaction to Next Paint (INP): how quickly the page visibly responds when someone taps, clicks or types. It replaced First Input Delay as a Core Web Vital in March 2024.
- Cumulative Layout Shift (CLS): how much the content moves around unexpectedly as the page loads, such as a button jumping just as you tap it.
Lab scores and real visitors
Google PageSpeed Insights shows two kinds of results. Lab data is a single simulated test on a mid-range phone, which is useful for finding problems. Field data comes from real Chrome users over the previous 28 days, and is what Google uses for Core Web Vitals. A new or low-traffic site may not have enough visitors to show field data yet.
What slows business websites down
The same culprits appear again and again:
- Large, uncompressed images and background videos
- Too many third-party scripts: chat widgets, trackers, review badges and booking embeds
- Heavy themes and page builders that load code for features you don’t use
- Fonts, banners and embeds that load late and push content around
- Slow or distant hosting
How to improve them
Most fixes are straightforward once you know where to look:
- Serve images in modern formats, at the size they are displayed
- Load the words first and add motion and extras afterwards
- Audit third-party scripts and remove what you don’t use
- Reserve space for images and embeds so the layout doesn’t jump
- Use hosting with a global edge network
Why we don’t promise a score
Scores move with every image, plugin and tracking script added after launch, and Google changes how it tests. We build every site mobile-first and speed-test it before launch, and our care plans include regular speed checks, but we won’t guarantee a number we don’t fully control.