Online Stopwatch
A simple, accurate browser-based stopwatch with lap time tracking. Click Start to begin, Lap to record a split, and Reset to clear. Great for workouts, cooking, studying, presentations, and more.
Lap Times
| Lap | Lap Time | Total Time |
|---|
How to Use the Stopwatch
- Start / Pause — Click the Start button to begin timing. Click it again to pause. The button label changes to reflect the current state.
- Lap — While the stopwatch is running, click Lap to record the current split. The lap table shows each split time and the running total.
- Reset — Clears the time and all recorded laps. You can also reset while the stopwatch is paused to keep the final time visible before clearing.
- Copy All — Copies all lap data to your clipboard as tab-separated text, ready to paste into a spreadsheet.
Common Uses for a Stopwatch
- Workouts and interval training — Time each set or rest period and use laps to record how long each exercise took.
- Cooking and baking — Time multiple steps simultaneously by using the running total and laps.
- Presentations and speeches — Practice timed presentations. The large display is easy to glance at without losing your place.
- Classroom and testing — Teachers can time reading activities, quizzes, or lab exercises. See the classroom timer if you need a countdown instead.
- Productivity and focus sessions — Track how long tasks actually take to improve time estimates. If you want a structured work/break rhythm, the hours calculator can help plan your sessions.
Stopwatch vs. Timer — What's the Difference?
A stopwatch counts up from zero, measuring elapsed time. A timer (countdown clock) counts down from a set duration and alerts you when it reaches zero. Use a stopwatch when you want to record how long something took; use a timer when you need to be notified after a specific interval.
Frequently Asked Questions
How accurate is this stopwatch?
This stopwatch uses the browser's performance.now() API, which has sub-millisecond resolution on modern browsers. The display updates every 50ms. Accuracy is limited primarily by JavaScript timer scheduling on your device, but is well within 10ms for typical use — more than sufficient for anything that doesn't require laboratory precision.
Does it keep running if I switch tabs?
Yes. The stopwatch records the actual elapsed wall-clock time using timestamps, not a simple interval counter. If you switch tabs and browsers throttle the timer, the time tracked remains accurate when you return — the display will simply catch up.
Can I record more than one stopwatch at a time?
Not within a single instance, but you can open multiple browser tabs or windows, each with its own stopwatch running independently.
Is there a maximum lap count?
No. You can record as many laps as you need. For very long sessions, the lap table is scrollable.
