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Stopwatch — Free Online Tool
Sometimes you just need a clean stopwatch without installing an app. This online stopwatch counts up in hours, minutes and seconds with three large controls: Start, Stop and Reset. Open the page on your phone, laptop or tablet and begin timing as soon as it loads, with no sign-up and no permissions. Teachers can time class activities, students can practise mock tests under exam conditions, cooks can track a slow simmer, and fitness enthusiasts can measure rest intervals or a run. Developers and testers also find it useful for timing how long a task or process takes. Pressing Stop pauses the count so you can resume with Start, and Reset returns the display to 00:00:00. The timer updates once per second, which suits most everyday jobs but is not meant for sports timing where fractions of a second matter. Keep the browser tab open while the stopwatch runs, because some mobile browsers slow down or suspend background tabs to save battery, which can make the displayed time lag. Everything runs locally in your browser, so there is nothing to download and no data is collected. For measuring the gap between calendar dates, use the Date Calculator.
Use our Stopwatch on AllConvertor — no registration, no download, works on iPhone, Android, Windows, and Mac. All processing runs in your browser when possible for maximum privacy and speed.
How to use Stopwatch
- Open the stopwatch page in your browser.
- Press Start to begin timing.
- Press Stop to pause when the activity ends.
- Press Reset to clear the display and start again.
Key benefits
- ✓ 100% free — no paywall or trial limits
- ✓ No account or email required
- ✓ Mobile-friendly responsive design
- ✓ Instant results in your browser
- ✓ Secure — data stays on your device
- ✓ Trusted by thousands of users daily
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Frequently Asked Questions
How do I use the online stopwatch?
Press Start to begin counting, Stop to pause and Reset to return to zero. The display shows hours, minutes and seconds.
Does this stopwatch show milliseconds or laps?
No. It updates once per second and has no lap button, so it suits everyday timing but not precise sports measurements.
Will the stopwatch keep running if I switch tabs?
Browsers may throttle background tabs, especially on mobile, so keep the tab open and visible for the most accurate time.
Does it work on mobile phones?
Yes. The controls are large and responsive, and it runs in any modern mobile or desktop browser.
Can I use it for exam practice?
Yes. Start it when you begin a mock test and stop when you finish to see how long each paper takes.