In May 2021, Google launched Core Web Vitals. It is a collective term for three technical parameters that, in conjunction with other parameters, ensure users have a good site experience when they visit your website. The launch is an extension of the already existing Web Vitalswhich emphasizes parameters such as mobile-friendliness and HTTPS.
With the launch of Core Web Vitals, Google has added more technical parameters to the evaluation criteria that Google uses to determine your website's quality and thus visibility in search results. Google has officially confirmed that the new Core Web Vitals parameters have a direct impact on your website's visibility in search results.
The 3 elements of Core Web Vitals
Core Web Vitals basically consists of three technical metrics of your website that must meet certain criteria to ensure a good site experience for users:
- Largest Contentful Paint (LCP). LCP refers to the speed of how long it takes to display the element on the page that takes up the most space. This is typically the largest image on the page. To ensure a good page experience, LCP should be a maximum of 2.5 seconds.
- First Input Delay (FID). FID refers to the time it takes for the page to respond to user input (for example, when a visitor clicks on a link or button). To ensure a good page experience, the FID should be no more than 100 milliseconds.
- Comulative Layout Shift (CLS). CLS refers to how much elements on the page move during page load. To ensure a good page experience, CLS should be no more than 0.1. Especially on mobile devices, the CLS score is highly valued as page movement is clearly visible.
In addition, a number of supplementary measurements of a less significant nature are included, including First Contentful Paint (FCP), Interaction to Next Paint (INP) and Time to First Byte (TTFB). If you're curious, you can read more about these metrics in Google's own guide.
Optimization of Core Web Vitals
Use Google's free tool PageSpeed Insights to analyze Core Web Vitals on your website. The tool analyzes one page of your website and gives it a score from 0-100 on mobile and desktop devices respectively. You also get a detailed report with concrete recommendations on how to improve Core Web Vitals on the site.
You should analyze different types of pages on the website (for example, the front page, a category page and a product page) to make sure that all pages have a good score. Often, improvements on one page will have a positive impact on the entire site because the pages are built on the same technical platform.
The score is calculated based on actual user data, i.e. the visitors' actual experience on your website. Be aware that it is virtually impossible to achieve a score of 100. Google itself says that a page is good if it has a score of 90 or above. A page needs improvement if it has a score of 50-89 and a page is really bad if it has a score of 0-49.
A good complement to PageSpeed Insights is the "Key web statistics" report in Google Search Console. Here you get an ongoing analysis of which pages on your website have a good, average and poor Core Web Vitals score and the reason for any poor score.
