Stopwatch

Accurate time measurement with lap recording

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Tap to Start/Stop

What is an Online Stopwatch?

An online stopwatch is a precision timing tool you can use right in your browser. It measures elapsed time down to the millisecond and includes lap recording so you can track individual intervals. No app installation is needed; it works instantly on any PC, smartphone, or tablet.

User Guide

  1. Click the Start button or press the Space key
  2. Press the Lap button or L key to record an interval
  3. Click Stop or press Space again to pause
  4. Review your times, then press Reset or R to clear everything

Core Features

  • Millisecond precision - Measures time accurately to 1/100th of a second
  • Unlimited lap times - Record as many intervals as you need
  • Best/worst lap highlight - Automatically marks your fastest and slowest laps
  • Interval differences - Shows the time gap between consecutive laps
  • Keyboard shortcuts - Space (start/stop), L (lap), R (reset) for quick control

When This Comes in Handy

  • Sports and training - Track running, swimming, and cycling intervals
  • Cooking - Time recipes precisely for consistent results
  • Game speedruns - Record completion times and analyze segment performance
  • Study sessions - Measure study time per subject to allocate efficiently
  • Presentation practice - Rehearse speeches to stay within your time limit

Common Questions

Q: How accurate is this stopwatch?

It uses the browser's high-resolution timer and measures down to the millisecond. This is more than accurate enough for everyday tasks, though official sports events should use dedicated timing equipment.

Q: Does it keep running in the background?

Yes, the stopwatch continues while you use other tabs or apps. However, some browsers throttle background tab timers, so keep the tab active if you need exact millisecond precision.

Q: Is there a limit on the number of laps?

There is no practical limit. You can record hundreds of laps without issues. The lap list scrolls so you can always review earlier entries.

Q: Can I save my records?

There is no automatic save feature at this time. For important records, take a screenshot or manually note the times before resetting.

Q: Do keyboard shortcuts work on mobile?

They work on tablets with a physical keyboard connected. On smartphones, use the on-screen buttons to control the stopwatch.

Q: How are best and worst laps shown?

Once two or more laps are recorded, the fastest interval is highlighted in green and the slowest in red. This makes it easy to spot your strongest and weakest segments at a glance.

Q: Is there a countdown feature?

This tool is a stopwatch only, measuring elapsed time upward. If you need a countdown, check out the dedicated Countdown Timer tool on this site.

Q: Does it have sound alerts?

The current version does not include sound alerts. Time is displayed visually on screen.

Q: Will refreshing the page lose my data?

Yes. Refreshing or closing the browser tab clears all active timing and lap records. Always save important results before navigating away.

Q: Do I need to install anything?

No. The stopwatch runs entirely in your web browser with no downloads or plugins required. It works on desktop, mobile, and tablet devices.

How It Works

The stopwatch uses performance.now() for millisecond-precise timing. It stores the start timestamp and calculates the difference from current time each frame via requestAnimationFrame. Features include lap recording, pause/resume, and reset, with best/worst lap times highlighted.

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Further Reading