Latency numbers every frontend developer should know

Latency in web page load times and responsiveness to user action is a crucial factor affecting user satisfaction. It depends on the user's connection type (Wifi, LTE, 5G), server distance, and network quality. Low latency numbers can compound quickly, impacting overall performance. Key metrics include Wifi latency, 5G high-band and mid-band latencies, TTFB, FCP, LCP, frame duration at 60fps, round trip latencies to different locations, time to parse CSS, HTML, JS, and INP. These numbers can vary based on device type and network quality.