Responsible JavaScript

Averages tend to be skewed since large collections of field metrics have many outliers. Focus on percentiles. The 75th, 90th, and 95th percentiles are especially valuable, as these intervals tend to emphasize slower experiences over faster ones. Pay special attention to the 90th percentile and up. This is where you’ll see how slower devices and poor network conditions affect performance. Address pain points in this range, and you’ll make your website faster for everyone regardless of how fast their network connection or device is.