Core Web Vitals are a set of specific factors that Google considers important in determining the quality of the user experience provided by a web page. They are part of Google’s larger effort to encourage better web performance and user experience. There are three core web vitals:

1. Largest Contentful Paint (LCP): This measures loading performance and specifically looks at the render time of the largest content element visible within the viewport. It indicates how quickly the main content of a page loads. Google recommends that LCP should occur within 2.5 seconds of when the page first starts loading.

2. First Input Delay (FID): FID measures interactivity and responsiveness. It quantifies the time from when a user first interacts with a page (e.g., clicks a link, taps on a button) to the time when the browser can respond to that interaction. It’s important for users to perceive a page as responsive. Google recommends that pages have an FID of less than 100 milliseconds.

3. Cumulative Layout Shift (CLS): CLS measures visual stability. It quantifies how much content shifts around during the loading process. This is important because unexpected layout shifts can be frustrating for users, especially if they accidentally click on the wrong element due to a shift. Google recommends that pages maintain a CLS of less than 0.1.

These metrics are crucial for us to consider when building your website because they directly impact user experience and can affect a site’s ranking in Google search results. Starting from May 2021, Google integrated these core web vitals into its ranking algorithm as part of the broader Page Experience update.