Stopwatch

What this stopwatch does

This stopwatch counts up from zero and records laps while it runs. You can start it, pause it, mark a lap, and reset it back to zero. The display refreshes several times a second, so the numbers move smoothly.

Timing comes from your computer's clock, not from counting ticks inside the page. That matters when you switch tabs or your device goes to sleep. The stopwatch reads the current time when it starts and compares it to the current time now. The gap between those two moments is your elapsed time. A background tab cannot slow that down.

You can also run the stopwatch in full screen. That view shows only the clock, which helps when you glance at it from across a room.

Start, stop, lap, reset

Four controls cover everything. Start begins the count. Stop pauses it at the current time. Lap records a split without stopping the clock. Reset clears the elapsed time and all laps.

When you press Lap, the stopwatch saves two numbers. The split is the time since your last lap. The running total is the time since you started. Both appear in the lap list, so you can see how fast each segment was and where you stand overall.

Say you run four laps of a track. Your splits might read 1:32, 1:29, 1:35, and 1:31. The running totals would read 1:32, 3:01, 4:36, and 6:07. The split tells you about that one lap. The total tells you about the whole session.

Laps keep recording while the stopwatch runs. If you pause and start again, the clock picks up where it left off. The lap list stays in order.

Keyboard shortcuts

You can run the whole stopwatch without touching the mouse.

• Space starts and pauses the stopwatch.
• L records a lap.
• R resets the stopwatch and clears the laps.

These keys work the same way on the timer and the countdown, where Space starts and pauses. On the stopwatch, L and R add lap and reset.

One warning about Space: if a button still has focus after you click it, the browser may treat Space as a second click. Click on the page background first if the stopwatch starts and stops on its own.

What it is good for, and what it is not

This stopwatch suits practice, not official competition. Coaches and referees at sanctioned events use certified timing equipment that is tested and sealed. A browser stopwatch has no such certification. Use it for training, cooking, classroom activities, and everyday timing at home or work.

Common uses include rests between sets (60 to 90 seconds), plank holds (30 to 60 seconds), HIIT work intervals (20 to 45 seconds), and reading sprints (15 to 25 minutes). It also works for steeping tea, timing a quiz section, or tracking how long a task really takes.

If you need a countdown instead of a count up, the Pomodoro timer runs 25 minute focus blocks with 5 minute breaks. The 5 minute timer handles shorter waits. For dates rather than durations, try the date calculator.

Accuracy and limits

The stopwatch depends on your device's clock. If that clock is wrong, the stopwatch is wrong by the same amount. Most phones and computers sync their clocks over the network, so the error is usually tiny.

Browser timing is fine for sport practice and cooking. It is not an official sports timer. No browser tool can promise the precision of a timing system used at a meet.

If you reload the page while a timer runs, the end time is stored in the browser for that tab, so the timer survives the reload. The stopwatch itself starts fresh after a reload, because it counts up rather than toward a fixed end.

Questions people ask

Does the stopwatch keep running in another tab?

Yes. It reads your computer's clock, so switching tabs or letting the screen sleep does not change the elapsed time. When you come back, the display catches up to the correct total.

What is the difference between a split and a lap time?

The split is the time for one segment, measured from your last lap press. The running total is the time since you started. The lap list shows both, so you can compare segments and see the overall picture.

Can I use this for a race or a school record?

For practice, yes. For anything official, no. Sanctioned events need certified timing equipment. A browser stopwatch is a training and everyday tool, not a replacement for a meet timing system.

How many laps can I record?

There is no fixed limit in the tool. The lap list grows as you press L or tap Lap. Very long lists may slow an older device, so reset between sessions if the page feels sluggish.

Why did my stopwatch stop when I pressed Space twice?

Space starts and pauses the stopwatch. If a button still has keyboard focus, the browser may also treat Space as a click on that button. Click the page background first, then use the keyboard.