Stopwatch

What Is the Stopwatch?

The Stopwatch measures how much time passes, starting from zero and counting up. It shows elapsed time in hours, minutes, seconds, and fractions of a second, so you can time an activity precisely. It is useful for workouts, study sessions, cooking, games, presentations, and any task where you need to know how long something took. Unlike a countdown timer, which counts down to zero from a set duration, a stopwatch counts up from zero until you stop it.

How to Use the Stopwatch

1. Open the Stopwatch page and check that the display shows 00:00:00 before you start.
2. Click Start to begin timing. The display updates continuously while the stopwatch runs.
3. Click Lap or Split if the tool offers it, to record the time at a checkpoint without stopping the main timer.
4. Click Pause to stop the display temporarily. Click Start again to resume from where you left off.
5. Click Stop when the activity is finished, then read the final elapsed time.
6. Click Reset to return the display to zero before timing something else.

Worked Example

Suppose you want to time a 5 km run. Click Start as you set off and click Stop when you finish. If the display shows 00:27:42.35, your run took 27 minutes, 42 seconds, and 35 hundredths of a second. If you pressed Lap at each kilometre, the lap list shows how long each kilometre took, while the main display keeps the total time. Comparing lap times can show whether you ran faster at the start or the end.

Limitations

• The displayed precision depends on the device and browser. The hundredths shown are useful for comparison, but they are not a certified timing measurement.
• The timer is meant for everyday timing. It is not a substitute for professional timing equipment in competitions or safety-critical work.
• If you reload or close the page, the elapsed time is normally lost, because the stopwatch keeps its state in the open page.
• Switching tabs or letting a device sleep can affect display updates on some devices, even though the underlying timer keeps counting.

Frequently Asked Questions

What is the difference between a stopwatch and a timer?

A stopwatch counts up from zero and measures elapsed time. A timer counts down from a set duration and alerts you when it reaches zero. Use a stopwatch to measure how long something took, and a timer to limit how long something should take.

What is a lap time?

A lap time is the time for one part of an activity, recorded without stopping the main timer. For example, in a race, each lap is one circuit, and the stopwatch can record each lap while the total keeps running.

Does the stopwatch keep running if I switch tabs?

In most browsers the timer keeps counting in the background, but the display may update less often while the tab is hidden. Return to the tab to see the current time.

Will the stopwatch keep running if I reload the page?

No. Reloading the page normally resets the stopwatch to zero. If you need a record, note the time or copy the lap list before reloading.