Core Web Vitals
Core Web Vitals are the subset of Web Vitals that apply to all websites, should be measured by all website owners, and are displayed using many Google tools. Each of the Core Web Vitals represents a specific facet of the user experience, is measurable in practice, and reflects real-world experiences with a key user-centric outcome.
These metrics were introduced by Google
Largest Contentful Paint (LCP): This metric measures the time it takes for the main content of a page to load. The search engine defines 2.5 seconds or faster as the ideal value. From 4 seconds it takes too long and should be optimised.
First Input Delay (FID): FID measures the time from the first interaction of a user with a page to the time at which the browser can react to this interaction. That is, clicking, scrolling, etc. . This indicates how quickly the website is responsive. 100ms would be optimal here.
Cumulative Layout Shift (CLS): The key figure CLS measures the visual stability of a website and whether individual layout elements shift during use. Google specifies 0.1 or lower as the ideal value.
What influence do the values have on SEO?
Google plans to introduce a new ranking factor - the Page Experience Signal. This will then combine the Core Web Vitals with existing User Experience Signals such as Mobile-Friendliness or HTTPS-Security. Content aspects, however, are not included. The Page Experience Signal is to be based primarily on technical factors. However, if two pages are similarly relevant in terms of content, the page with the better Page Experience Signal can take a higher ranking. But even if UX becomes more important, content will always decide the ranking factor and should therefore be in the foreground.