The 3 Core Web Vitals are performance metrics that measure the quality of user experience for web pages. These metrics are:
- Largest Contentful Paint (LCP): This measures the loading performance of a page and is an important factor in how quickly the page appears on a user’s screen. For example, if a page has a slow LCP, it may take longer for the main content of the page to become visible to the user.
- First Input Delay (FID): This measures the interactivity of a page and is an important factor in how quickly a user can begin interacting with the page. For example, if a page has a long FID, it may take longer for the user to be able to click on buttons or links on the page.
- Cumulative Layout Shift (CLS): This measures the stability of a page and is an important factor in how well the page layout holds up during loading and user interaction. For example, if a page has a high CLS, elements on the page may shift around as the page loads, which can be disorienting for users.
These metrics are important because they can affect the usability and perceived performance of a web page, and poor scores in these areas can lead to a negative user experience.