Time anything with this free online stopwatch. Start, stop, reset, and record lap times — accurate to hundredths of a second, right in your browser.
Laps:
1. Press Start to begin timing. 2. Press Lap to record a lap time while it keeps running. 3. Press Stop to pause, and Reset to clear everything back to zero.
A stopwatch measures how long something takes, from a fraction of a second to many hours. This free online stopwatch shows hours, minutes, seconds and hundredths of a second, and it lets you record lap times while it keeps running. There is no app to install and no sign-up: open the page, press Start, and time anything — a race, a workout, a cooking step, a study session or a game.
Stopwatches are used everywhere. Athletes time sprints and laps, students time exams and study sessions, cooks time recipes, teachers time tests, and workers time tasks. A stopwatch on a website is handy because it works on any device: a phone, a tablet or a computer. The lap button is the most useful feature: it records the time of each lap without stopping the clock, so you can compare laps and see if you are getting faster or slower.
Imagine you are timing a 100-metre sprint. Press Start when the runner begins. The display runs up: 00:00:05.00 after five seconds, 00:00:10.58 when the runner crosses the line, and you press Stop. The result is 10.58 seconds. For a longer event, such as a 400-metre race with four laps, press Lap at the end of each 100 metres. The lap list might show Lap 1: 00:00:12.34, Lap 2: 00:00:24.71, Lap 3: 00:00:37.05 and Lap 4: 00:00:49.80, so you can see that the runner slowed down in the last lap. Press Reset to clear the laps and time the next race.
The stopwatch reads the time from your device's clock, not from counting ticks, so it stays accurate even if your browser is busy. When you press Start, it notes the current time; the display is updated about 30 times a second to show the time that has passed. Pressing Stop freezes the display and saves the elapsed time, so pressing Start again continues from where you stopped. Pressing Lap copies the current display into the lap list without stopping the clock. Reset clears the elapsed time, the laps and the display back to 00:00:00.00.
Use laps for repeated events. Press Lap at each round or rep instead of stopping and starting again. Keep the page open. The stopwatch runs in this page, so do not close the tab while you are timing something. Press Stop before you read the time. The display updates many times a second, so stop it first to read the exact result. Use it for study sessions. Time 25 minutes of focused study, then take a 5-minute break, and repeat. Compare your laps. Look at the lap list to see your fastest and slowest laps and where you can improve.
Imagine you are timing a runner on a running track. Press Start when the runner begins. At the end of the first lap, press Lap: the list shows Lap 1: 00:01:12.34, which means 1 minute and 12.34 seconds. At the end of the second lap, press Lap again: Lap 2 shows 00:02:24.71, which is the total time since the start, not the time of the second lap alone. After the third lap, Lap 3 shows 00:03:37.05. To find the time of the third lap only, subtract the second lap from the third: 3 minutes 37.05 seconds minus 2 minutes 24.71 seconds is 1 minute 12.34 seconds. Press Stop at the finish, then Reset before the next race.
Pressing Reset by accident. Reset erases all your laps at once, so only press it when you are finished. Reading the display while it runs. The numbers change many times a second, so press Stop first to read the exact time. Forgetting that laps are total times. Each lap shows the total time since the start, so subtract the previous lap to get one lap's time. Closing the tab while timing. The stopwatch lives in this page, so closing the tab loses your time and laps. Using a stopwatch for official races. This tool is accurate for practice and everyday timing, but official races need certified equipment.
Pro Tip: Time the same task three times and take the middle result. One timing can be lucky or unlucky, but three timings show the real pattern.
Note: The stopwatch reads your device's clock, so it stays accurate even if the page is busy. The display updates about 30 times a second.
How accurate is this stopwatch? It shows hundredths of a second and reads your device's clock, so it is accurate for everyday timing such as sports, cooking and studying. It is not certified for official races.
Can I record lap times? Yes. Press Lap while the stopwatch is running and the current time is added to the lap list. The clock keeps running, so you can record as many laps as you like.
Does the stopwatch keep running if I switch tabs? The timing is based on your device's clock, so the elapsed time stays correct when you come back. The display may update less often while the tab is hidden, but the result is still right.
Can I pause and continue? Yes. Press Stop to pause, then press Start again to continue from the same time. Press Reset only when you want to start from zero.
Is there a limit on how long it can run? No. It can run for hours and shows hours, minutes, seconds and hundredths of a second. After 99 hours it keeps counting the hours.
Do I need to install anything? No. This stopwatch works in your browser on any phone, tablet or computer, with no app and no sign-up.
What is the difference between a lap and a split? They mean the same thing here: a recorded time during a run, such as the time at the end of each lap, while the clock keeps running.
Can I time something longer than an hour? Yes. The display shows hours, minutes, seconds and hundredths, so it can time events lasting many hours.