Count up, mark every lap
A timer counts down to a moment you chose in advance. A stopwatch answers the opposite question: how long did that take? Press Start and the time counts up in minutes, seconds and hundredths until you stop it.
Laps turn one measurement into many. Press Lap at every split and the list shows each lap time next to the running total, with the fastest and slowest lap marked once there are two to compare. When you are done, download the laps as a CSV file for a spreadsheet.
The time is worked out from when you pressed Start, not counted tick by tick, so switching tabs, locking the screen or a slow device never makes it drift.
How to use the stopwatch
Buttons, or the keyboard when you need your eyes elsewhere.
Press Start (or Space). The display counts up in minutes, seconds and hundredths.
Press Lap (or L) at every split. Each lap appears with its own time and the total so far.
Pause and resume as often as you need. Reset (or R) clears the time and laps; download the laps first if you want to keep them.
What it does
A plain stopwatch with the parts people actually use.
- Hundredths of a second, with an hour field after 60 minutes
- Unlimited laps with lap time and running total
- Fastest and slowest lap marked automatically
- Pause and resume without losing time
- Keyboard shortcuts: Space, L and R
- CSV download of all laps
- Full screen for a projector or a gym wall
- Keeps correct time in background tabs and after a reload
Where people use it
Anywhere you need to know how long something took.
A running coach times eight laps of the track and compares the splits afterwards.
A physics class times a pendulum over ten swings to work out one period.
A speaker rehearses a talk and laps each section to see where the minutes go.
A cook times the stages of a recipe without setting a target in advance.
A swimmer's parent records each length from the stands.
A board game group measures how long each player's turn takes.
How the time is kept
The stopwatch stores the moment you started and the time already counted before any pause. The display is recomputed from those two facts many times a second, so the number on screen is always the real elapsed time, even after the browser slowed the page down in the background.
A lap stores the total at the moment you pressed it. The lap time is the difference from the previous lap. Pressing Lap twice at the same instant, or before anything has been timed, does nothing.
Good to know
It measures time on your device; it is not an official timing system for races with records or results that must be certified.
Your reaction time is part of every press, as with any hand-held stopwatch.
The time and laps are kept in this browser. Clearing site data resets them.
Tips
- Use full screen on a projector so a whole class or team can see the time.
- Use the keyboard shortcuts when you are watching the runner, not the screen.
- Download the CSV before pressing Reset if you want to compare sessions later.
Stopwatch questions
Does it keep counting in another tab?
Yes. The time is calculated from when you pressed Start, so it is correct whenever you look again.
How precise is it?
The display shows hundredths of a second. The press itself is as precise as your finger, like any hand-held stopwatch.
How many laps can I record?
As many as you need. The fastest and slowest lap are marked once there are at least two.
Can I export the laps?
Yes. Download them as a CSV file with lap number, lap time and total, ready for a spreadsheet.
What is the difference from the timer?
The timer counts down from a time you set; the stopwatch counts up from zero until you stop it.
Are there keyboard shortcuts?
Space starts and pauses, L records a lap and R resets.