perfume.js
Web performance library for measuring all User-centric performance metrics, including the latest Web Vitals.
statman-stopwatch
statman-stopwatch is one of the metrics from the statman library. It is a simple high res stopwatch for node.js. Stopwatch is useful for determining the amount of time it takes to perform an activity.
sitespeed.io
sitespeed.io is an open-source tool for comprehensive web performance analysis, enabling you to test, monitor, and optimize your website’s speed using real browsers in various environments.