What are the key metrics to monitor when optimizing website speed?

When you’re working on website speed, keep a close eye on metrics like page load time, Time to Interactive (TTI), Largest Contentful Paint (LCP), First Contentful Paint (FCP), First Input Delay (FID), and Total Blocking Time (TBT). These help you understand how quickly your site becomes usable. You’ll also want to track server response time and the number of HTTP requests, since they directly impact how fast your content loads.