Online Stopwatch
Press Start, then Lap as often as you like. The clock keeps the right time through a refresh, a locked phone or a closed tab.
Chart: lap times
Saved sessions
How to use the stopwatch
Press Start and the digits begin to run in minutes, seconds and hundredths, with hours added once you pass the hour. The same button turns into Stop. Stopping only pauses the clock: press Start again and it carries on from where it stopped, so breaks are left out of the total.
While it runs, the left button is Lap. Each press adds a row to the lap table, newest on top. Under the big digits you can always see how long the current lap has been going. When the clock is stopped the left button becomes Reset, which clears the clock and keeps the finished run in Saved sessions. Reset can be undone from the message that appears, or with Undo, which also removes the last lap if you pressed Lap by mistake.
Tap the lap number in the table to give that lap a name, such as a runner, a song or a step in a recipe. Full screen makes the digits as wide as the screen, and Keep screen on stops a phone from going dark while you watch it.
Laps and splits
This stopwatch with laps records two times on every press. The lap time is the time since the last lap press (or since the start, for lap 1). The split is the total time on the clock at that press, so the split of your latest lap is the running total. The +/- column compares each lap with the one before it: a plus sign means that lap was slower, a minus sign means it was faster.
The fastest lap is marked in green and the slowest lap is tagged, and the boxes above the table show the number of laps, the average lap (total time at the last lap divided by the number of laps), the fastest and the slowest. Lap times are recorded to the hundredth of a second, so every lap time, split and difference on screen adds up exactly.
Open Chart to see every lap as a bar with a dashed line at the average. Download CSV saves the current run for a spreadsheet, Print sheet prints its lap table, and in Saved sessions you can download one past session or all of their laps in one file. Share link copies a link with the laps you have so far, as a stopped stopwatch, never as a clock that is still running.
Counting laps around a track or a pool with a tap anywhere on a large area, with distance and pace? The lap counter is made for that. For work and rest periods that count down by themselves, use the interval timer, or the round timer for boxing rounds with a bell.
Keyboard shortcuts
- Space: start or stop
- L or Enter: record a lap while the clock runs
- R: reset (stops first if it is running; the message offers Undo)
- U or Ctrl+Z: undo the last lap or a reset
- F: full screen
- M: sound on or off
Holding a key down does not repeat it, so a long press on Space or L counts once. A lap press also beeps when Sound is on and vibrates on phones that support vibration when Vibrate is on.
Questions
Does it keep running if I close the tab or lock my phone?
Yes, in the sense that matters: the time stays right. The page does not count ticks. It saves the moment you pressed Start in your browser and works out the elapsed time from your device clock whenever it draws the digits. Nothing runs while the tab is closed or the phone is locked, so no lap can be recorded and no sound plays then, but when you come back, or reopen the page after the browser was fully closed, it reads the saved start time and shows the correct elapsed time, still running. This needs the same browser with its site data kept: a private window forgets everything when it closes, and changing the device clock while the stopwatch runs shifts the time by the same amount.
Does the stopwatch work offline?
Once the page has loaded, yes. All the timing happens in your browser and nothing is sent to a server, so losing the connection does not stop it. On most browsers the site also keeps a copy of its pages after your first visit, so the stopwatch usually opens without a connection as well.
How accurate is this online stopwatch?
The time comes from your device clock, which keeps time far more precisely than the hundredths shown. Hundredths are cut off rather than rounded, so 59.999 seconds shows as 0:59.99 and never jumps ahead to 1:00.00 early. In practice the limit is the moment you press the button, which depends on your reaction, so use it for training, games and everyday timing rather than official results.
Where are my past sessions saved?
Every time you press Reset after a run, that session (start date, total time and all laps with their names) is added to Saved sessions under the stopwatch. The last 20 are kept in this browser only. You can download one as a CSV file, download every lap of every session together, or delete one (Undo brings it back).
What is the difference between a lap timer and a split timer?
They are the same tool looked at in two ways. A lap timer shows how long each lap took, and a split timer shows the running total at each press. This page shows both on every row, plus the difference to the lap before.
More in Sport and fitness
Put this online stopwatch on your website
Free for classrooms, clubs, blogs and shops: paste this code into any page. It works the same inside your site, and counts stay in each visitor's own browser. For a dark version, add ?theme=dark after /stopwatch/ in the code.