How Stopwatch Works
Rather than simply counting up on a timer tick, the stopwatch records the exact moment you press Start and compares it against the current time on every update. That means the display stays accurate to the millisecond even if the browser tab is throttled in the background, unlike a stopwatch that just increments a counter once per interval.
How to Use This Tool
- Select Start to begin timing.
- Select Pause to freeze the display, and Start again to resume from where you left off.
- Select Lap at any point while running to record the current elapsed time to the lap list.
- Select Reset to clear the timer and lap list and start over from zero.
Example
Start the stopwatch, let it run for a minute and a half, then tap Lap — the lap list logs 00:01:30.00 as Lap 1. Keep the stopwatch running, tap Lap again 45 seconds later, and Lap 2 shows 00:02:15.00 with a split of 00:00:45.00 since the previous lap.
Helpful Tips
- Use Lap to break a long activity into segments — each lap shows both its total elapsed time and its split from the previous lap.
- Pausing does not clear the clock, so you can stop and resume as many times as you need before resetting.
- Because timing is based on real timestamps rather than a simple counter, it stays accurate even if you switch tabs while it's running.
Frequently Asked Questions
How accurate is this stopwatch?
It reads your device's clock directly and displays time down to the centisecond (hundredths of a second), so it stays accurate even under heavy browser load.
Does Pause reset the elapsed time?
No. Pause simply freezes the display; selecting Start again resumes counting from the paused time.
What does the split time on a lap mean?
Each lap shows the total elapsed time since Start, and the split is the time that passed since the previous lap was recorded.
Will the stopwatch keep running if I close the tab?
No — timing state lives only in the page. If you close or reload the tab, the stopwatch resets.
This tool runs entirely in your browser. Your input is not uploaded to any server.