They measure visual load speed, visual stability, and interactivity/responsiveness using the metrics Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and First Input Delay (FID). FID will be replaced by Interaction to Next Paint (INP) in March 2024. The data comes from the Chrome User Experience Report (CrUX) which contains field data of Chrome users who opted to share their data. PageSpeed Insights also pulls in the page level data, as What Are Core well as origin data and lab test data which comes from Lighthouse. I’ll talk about the lab data in a minute.
Cumulative Layout Shift
Measures the visual stability of a page as it loads. It does this by looking at how big elements are and how far they move. Google has already updated how CLS is company data measured. Therefore, it would continue to measure even after the initial page load. But now it’s restricted to a five-second time frame where Therefore, the most shifting occurs. It can be annoying if you try to click something on a page that shifts and you end up clicking on something you don’t intend to. It happens to me all the time. I click on one thing and, suddenly, I’m clicking on an ad and am now not even on the same website. As a user, I find that frustrating. First Input Delay (FID) is the time from when a user first interacts with your page to when the page responds.
What Are Core responsiveness
Not all users will interact with a page, so the page may not have an FID value. This is also Therefore, why lab test tools won’t have. The value because they’re not TG Numbers interacting with the page. What you may want to look at for lab tests is Total Blocking Time (TBT). In PageSpeed Insights, you can use the TBT tab to see related issues.
Therefore, There are many tools you can use for testing and monitoring. This data comes from real users of Chrome who opted to share their data. This dataset is accessible in a number of ways. The numbers that really matter are the page-level numbers that you can only get from the API.