Thanks for tuning in to Google I/O! Watch content on-demand . web.dev Explore Metrics Stay organized with collections Save and categorize content based on your preferences. Metrics Measuring performance and user experience. Overview User-centric performance metrics are a critical tool in understanding and improving the experience of your site in a way that benefits real users. Introduction User-centric performance metrics Important metrics to measure Largest Contentful Paint (LCP) Cumulative Layout Shift (CLS) Interaction to Next Paint (INP) Time to First Byte (TTFB) First Contentful Paint (FCP) Total Blocking Time (TBT) Define your own metrics Custom metrics