About this online stopwatch
This stopwatch times anything from a sprint to a long meeting, showing minutes, seconds, and hundredths of a second, and switching to hours after the first hour. Press Lap to record a lap while the clock keeps running: the table lists each lap time and the split, which is the total time when the lap was taken. With two or more laps, the fastest is shown in green and the slowest in red, and the bars compare every lap with the slowest one. Timing uses the browser’s high-resolution clock, so it stays accurate when you switch tabs.
How to use the stopwatch
- Press Start. The clock and the dial start running. The browser tab also shows the time.
- Record laps. Press Lap, or the L key, each time a lap ends. The newest lap appears at the top of the table.
- Stop and resume. Press Stop to pause and Resume to continue from the same time, or use the space bar.
- Save or reset. Press Copy laps to paste them into a spreadsheet, or Download CSV. Press Reset, when stopped, to start over.
Frequently asked questions
What is the difference between a lap time and a split?
A lap time is how long that one lap took. A split is the total elapsed time when the lap was recorded. For laps of 1:05 and 1:10, the second split is 2:15.
How accurate is the stopwatch?
It reads the browser’s performance clock, which is precise to well under a millisecond, and shows hundredths. Your reaction time when pressing the button is the main source of error.
Does it keep running if I switch tabs or lock my phone?
It keeps measuring time while the page stays open, because elapsed time is calculated from the clock rather than counted. Closing or reloading the page clears it.
Why can I not reset while it is running?
To avoid losing a timing by accident, Reset only works when the stopwatch is stopped. Press Stop first, then Reset.