Chronometer

Simple stopwatch and timer tool

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Start
Lap
Reset

TL;DR

What is Chronometer?

A chronometer is a precise timekeeping instrument. In this context it is a browser-based stopwatch: start, stop, and reset to measure elapsed time with millisecond precision. Lap times let you record intermediate splits without stopping the overall timer.

Common use cases

  • Performance benchmarking: measure how long a manual process takes to establish a baseline
  • Presentations and demos: time a live walkthrough to stay within a session slot
  • Focus sessions: track time spent on a task using the Pomodoro or time-boxing technique

Frequently asked questions

How accurate is a browser-based stopwatch?

Browser timers use performance.now() which has sub-millisecond resolution in most browsers. However, browsers throttle timers in background tabs (Firefox and Chrome reduce resolution to 1ms or more). Keep the tab focused for the most accurate measurements.