What Is an Online Stopwatch?
An online stopwatch is a web-based tool that measures elapsed time with high precision. Unlike a simple timer that counts down, a stopwatch counts up from zero — perfect for measuring how long something takes. TrueTime.zone's stopwatch works directly in your browser with no app or installation required.
Whether you're timing a workout, a cooking task, a presentation, or a race, the stopwatch records time to the millisecond and lets you record lap splits at any point.
How to Use the Stopwatch
- Start / Pause: Click Start to begin timing. Click again to pause.
- Lap: Press Lap while running to record a split. Each lap shows the split time and total elapsed time.
- Reset: Click Reset to clear the timer and all lap records.
- Tip: The stopwatch continues if you switch browser tabs. Return to this page to see the updated time.
Features
- ✅ Millisecond precision — accurate to 10ms display
- ✅ Unlimited lap recording with split and total time
- ✅ Runs in background when you switch tabs
- ✅ No install, no login, completely free
- ✅ Works on desktop, tablet, and smartphone
- ✅ Clean dark mode interface
Frequently Asked Questions
Does the stopwatch keep running if I switch tabs?
Yes. The stopwatch uses the browser's high-resolution timestamp, so it keeps tracking time even when you switch to another tab. When you come back, the display updates immediately to show the correct elapsed time.
How accurate is this stopwatch?
The stopwatch uses
performance.now() — a high-resolution timer available in all modern browsers — which is accurate to sub-millisecond precision. The display updates every ~50ms for a smooth visual. For competitive timing, dedicated hardware stopwatches may be more reliable, but for everyday use this is extremely accurate.How many laps can I record?
There is no built-in limit. You can record as many laps as needed. The lap list is scrollable so you can always see older splits. Note that laps are not saved if you refresh or close the tab.
Does it work on mobile?
Yes. The stopwatch is fully responsive and works on iPhone and Android. Open it in Chrome or Safari. For best accuracy on mobile, keep the screen on while timing.
Can I use the stopwatch offline?
Once the page is loaded, the stopwatch itself runs entirely in JavaScript and does not need an internet connection. If you lose connectivity mid-session, the timer continues running normally. You'll need internet to reload the page.
Is it free?
Yes, completely free. All tools on TrueTime.zone are free and supported by display advertising.