Online Stopwatch

Free, browser-based timing with millisecond precision — no download, no sign-up.

00:00 .000 Ready
Shared result — timer is in read-only mode
Lap times

Press Lap while running to record a split

What is a Stopwatch?

A stopwatch measures elapsed time from a defined starting point, counting forward from zero. Unlike a clock that shows the time of day, a stopwatch answers a different question: how long did that take? — making it the go-to tool for athletes, students, researchers, coaches, and anyone who needs to measure duration precisely.

This online stopwatch runs entirely in your browser using the high-resolution Performance API, delivering millisecond-accurate results without any installation, account, or server connection. It works on any device — desktop, tablet, or mobile — in any modern browser.

Common uses include interval training and sprint timing, cooking and recipe timing, productivity sessions, lab experiments, and measuring how long any repeatable process takes across multiple attempts.

The lap recording feature lets you capture splits without stopping the clock, so you can compare individual segments side by side.

How to Use the Stopwatch

  1. Press Start The timer begins immediately and the progress ring starts rotating. Alternatively, press Space on your keyboard.
  2. Record a Lap While running, click Lap or press L. The current split is recorded without stopping the clock. Fastest and slowest laps are highlighted automatically.
  3. Pause at any time Click the Pause button or press Space again. The elapsed time is frozen and your lap data is preserved.
  4. Resume or Reset Press Start again to continue from where you left off, or click Reset (available while paused) to clear everything and return to zero.
  5. Switch themes Use the moon/sun icon in the control row to toggle between light and dark display — no page reload required.

Features

Everything you need for precision timing — and nothing you don't.

Millisecond precision Accurate to 0.001 s via the browser Performance API.
Lap recording Unlimited splits — delta vs best and running total per row.
Visual progress ring Animated SVG arc — one full rotation per minute.
Keyboard shortcuts Space L R — hands-free control.
Light & dark theme One-click toggle, no flicker, no reload needed.
Mobile-ready Responsive, touch-friendly, works in any modern browser.
100% client-side No data leaves your device. No backend, no tracking.
Best / worst highlighting Fastest lap in green, slowest in red — at a glance.

Frequently Asked Questions

Is this online stopwatch free to use?+
Yes — completely free, no sign-up, no ads, and no download required. Open the page and press Start.
How accurate is the online stopwatch?+
The stopwatch uses the browser's performance.now() API, which delivers sub-millisecond resolution — accurate to at least 0.001 s. This exceeds the requirement for training, sports benchmarking, and educational use.
Can I record lap times?+
Yes. Click Lap or press L while the stopwatch is running. Each entry shows the lap duration, the time difference versus your best lap, and the cumulative elapsed total. Fastest lap is highlighted green; slowest red.
Does the stopwatch work on mobile and tablet?+
Yes. The layout is responsive and the buttons are touch-optimised. It runs on iOS Safari, Android Chrome, and all modern mobile browsers — no app installation needed.
What happens if I refresh the page?+
Timing data is held in memory. A page refresh will reset the stopwatch. Keep the tab open to preserve your session.
What are the keyboard shortcuts?+
Space starts or pauses the stopwatch, L records a lap while running, and R resets after pausing. Shortcuts are disabled when a form field is focused.
Can I use this for competitive sports timing?+
This tool is well-suited for training, personal benchmarking, and recreational sports. For officially sanctioned competitions, a certified dedicated timing device may be required by the governing body.
Does it send any data to a server?+
No. Everything runs entirely in your browser. No timing data, lap records, or personal information is transmitted to any server.

Other Time Tools & Resources

More free timing and scheduling utilities — each built for a specific need.