Core Web Vitals: A Guide to Optimizing Performance

Core Web Vitals are a set of specific factors that Google considers important in a webpage’s overall user experience. They are made up of three specific page speed and user interaction measurements: Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS). ### Largest Contentful Paint (LCP) LCP measures loading performance. To provide a good user experience, LCP should occur within 2.5 seconds of when the page first starts loading. Optimizing images, deferring non-critical CSS, and improving server response times can help improve LCP. ### First Input Delay (FID) FID measures interactivity. To provide a good user experience, pages should have a FID of 100 milliseconds or less. Breaking up long tasks and using web workers can reduce FID. ### Cumulative Layout Shift (CLS) CLS measures visual stability. To provide a good user experience, pages should maintain a CLS of 0.1. or less. Always including size attributes on your images and video elements, and never inserting content above existing content can help reduce CLS. Focusing on these metrics will not only improve your site's ranking on Google but, more importantly, will create a better, less frustrating experience for your users.