How does Core Web Vitals measure page performance?
One of Google's ranking signals, Core Web Vitals measures how fast a page loads, how quickly it responds to interaction, and how visually stable it is.
LCP assesses how quickly the largest content block reaches the screen, INP the response given to an interaction, and CLS the sudden shifts during loading. When these metrics come out weak, the search engine judges the user experience inadequate and leaves the page behind. In the audit, render-blocking resources are stripped out, images are converted to modern formats and compressed, critical CSS is brought forward, unnecessary third-party scripts are pared back and the server response time is improved. Because of mobile-first indexing, all of these measurements are tested on the mobile experience first. Performance work isn't a one-off; every update can move the metrics again, so it calls for regular monitoring.