Core Web Vitals

Optimizing for the quality of user experience is key to the long-term success of any store on the web. For any store, Web Vitals can help you quantify the experience of your site and identify opportunities to improve. Similar to the Google Webmaster Tools(GWT) that helps you to evaluate and maintain your website's performance, the Core Web Vitals report shows how your pages perform based on real-world usage data. 

Core Web Vitals are the subset of Web Vitals that apply to all web pages, should be measured by all site owners, and will be surfaced across all Google tools. This is the user experience needs that all websites should be striving to meet. Specifically, Google identifies the core user experience needs as: loading, interactivity, and visual stability. Here’s how those user experience needs are measured.

Core Web Vitals Report

The Core Web Vitals report is based on three metrics -LCP, FID, and CLS and it shows URL performance grouped by status, metric type, and URL group (groups of similar web pages). However, if a URL does not have a minimum amount of data to generate the report data for any of these metrics, it is omitted from the report. Once a URL has a threshold amount of data for any metric, the page status is the status of its most poorly performing metric. 

In case, if you see the "No data available" screen, then it means either that your property is new in Search Console, or that there is not enough data available

Measuring User Experience With Core Web Vitals

As per Google, site owners can measure the quality of the user experience of their sites with these metrics:

• LCP: It stands for Largest Contentful Paint and measures the loading performance. It is the amount of time to render the largest content element visible in the viewport, from when the user requests the URL. Typically, the can be either image or video, or perhaps a large block-level text element. For providing a good user experience, the LCP should occur within 2.5 seconds of when the page first starts loading. If the LCP is greater than 2.5 seconds or less than and equals 4 seconds, then it needs an improvement and it is considered poor when it is greater than 4 seconds. 
• FID: It stands for First Input Delay and measures the interactivity. It is the time from when a user first interacts with your page i.e. when they click a link, tap on a button, and so on to the time when the browser responds to that interaction. This is essential on the pages where the user needs to do something because this is where the page has to become interactive. For providing a good user experience, pages should have an FID of less than 100 milliseconds. If the FID is in between 100 milliseconds to 300 milliseconds, then it needs an improvement and it is considered poor when it is greater than milliseconds.
• CLS: It stands for Cumulative Layout Shift and measures visual stability. It is the amount that the page layout shifts during the loading phase. The score is rated from 0 to 1, where zero indicates no shifting and 1 indicates the most shifting. This is important because having page elements shift while a user is trying to interact with it is a bad user experience. For providing a good user experience, pages should maintain a CLS of less than 0.1. If the CLS is greater than 0.1 and less than or equals 0.25, then it needs an improvement. If the CLSis greater than 0.25, then it is considered poor.

Tools To Measure Core Web Vitals

You can measure the Core Web Vitals using Google Search Console just by clicking on the Open Report button. The Chrome UX Report is another way to measure Core Web Vitals. You can also run a live performance test for individual URLs using the PageSpeed Insights testing tool or the Chrome Lighthouse tool. Once you have measured your report, then you can analyze if your site needs improvement.