Stopwatch
A simple, accurate online stopwatch with lap timing.
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What is it?
An online stopwatch measures elapsed time from the moment you press Start, with the ability to pause, resume, and record lap times along the way — just like a physical stopwatch.
Formula Explanation
Elapsed time is tracked by recording the exact start moment and comparing it to the current time on every update. Pausing simply stops that comparison and remembers the elapsed value so far; resuming continues from there rather than starting over. A lap time is the difference between the current elapsed time and the previous lap.
Example Calculation
Starting the stopwatch and pressing Lap at 1 minute, then again at 1 minute 45 seconds, records a lap split of 45 seconds for the second lap.
How to Use
- Click Start to begin timing.
- Click Lap at any point to record a split without stopping the clock.
- Click Pause to stop timing, or Resume to continue from where you left off.
- Click Reset to clear the stopwatch and all recorded laps.
Benefits
- Precise to the hundredth of a second.
- Supports pausing and resuming without losing your elapsed time.
- Tracks lap splits for interval-based activities.
Use Cases
- Timing workouts, runs, or interval training sessions.
- Tracking how long a task or study session actually takes.
- Timing presentations, speeches, or cooking steps.
What Your Result Means
The main display shows total elapsed time since you first pressed Start (including any paused gaps are excluded). Each lap shows both its individual split time and the cumulative total time at that point.
Tips
- Use Lap during a run or workout to compare pace across intervals.
- Pause instead of Reset if you need to briefly stop without losing progress.
- Keep the tab open and active for the most accurate long-duration timing.
Common Mistakes
- Clicking Reset instead of Pause, which permanently clears the elapsed time.
- Switching away from the tab for very long durations, which can occasionally affect timer precision in some browsers.
- Forgetting to click Lap before Reset, losing the recorded splits.
FAQs
How accurate is this stopwatch?
It updates every 50 milliseconds and displays time to the hundredth of a second, which is accurate enough for virtually all everyday timing needs.
Can I pause and resume without losing my time?
Yes, pausing keeps your elapsed time saved — resuming continues counting up from exactly where you paused.
What does the Lap button do?
It records the current elapsed time as a lap without stopping the stopwatch, letting you track splits during a continuous activity.
Does the stopwatch keep running if I close the tab?
No, timing only continues while this page stays open in your browser.
Keep this browser tab open and active for the most accurate timing.
Last updated: July 26, 2026