Online Stopwatch
Time anything to the hundredth of a second, with laps and split times.
Space start or stop, L lap, R reset, F fullscreen.
How to use the stopwatch
Press Start to begin timing. Press Lap to record a lap without stopping the clock. Press Stop to pause, then Resume to carry on from the same time, or Reset to clear everything.
Every lap appears in the list under the stopwatch, newest at the top. Once you have three laps or more, the fastest and slowest are labeled so you can spot them at a glance. Copy results puts the total and every lap on your clipboard as plain text, ready to paste into a message, a spreadsheet or your notes.
You can work entirely from the keyboard: Space starts and stops, L records a lap, R resets and F opens fullscreen. Turn on Keep screen awake if you need the display to stay on while the stopwatch runs.
Lap time vs split time
A lap time is how long one lap took on its own, measured from the previous lap. A split time, shown here as Total, is the time since you first pressed Start.
Say you run three laps of a track. If your totals are 1:30, 3:05 and 4:35, your lap times are 1:30, 1:35 and 1:30. Lap times show whether you're keeping a steady pace. Totals show where you are in the whole effort. The list shows both side by side, so you never have to do the subtraction yourself.
Accuracy in background tabs
Browsers slow down pages you aren't looking at to save power, so a stopwatch that simply counted ticks would drift. This one doesn't count ticks. It records the exact moment you pressed Start and works out the elapsed time from your device's high-precision clock every time the display updates.
That means you can switch tabs, check your email and come back, and the time will be correct the moment the page is visible again. The display shows hundredths of a second, while copied results keep milliseconds.
Closing or reloading the tab ends the session, because nothing is stored. If your device goes to sleep, timing may pause, depending on your system.
For the most consistent results, keep the stopwatch tab open in its own window and use the keyboard. A key press usually reaches the browser a little faster than a tap on a touch screen, and pressing the same key every time keeps your own reaction time steady from lap to lap.