Online Stopwatch
Start, pause and record lap times. It runs in your browser and keeps counting while you work in another tab.
Shortcuts: Space start or pause, L lap, R reset, F fullscreen
How to use the stopwatch
Press Start to begin. Pause freezes the time exactly where it is and Resume picks up from there, so the time you spent paused is never counted. Reset returns everything to zero and clears the lap list. If you prefer the keyboard, Space starts and pauses, L records a lap, R resets and F goes fullscreen.
Lap timing
Press Lap while the stopwatch is running to record a split. Each row shows the time for that lap on its own and the total elapsed time when you pressed it, with the newest lap at the top. Once you have two or more laps, the fastest and slowest are labelled so you can pick them out at a glance.
Lap times are worked out from the raw elapsed values rather than from the numbers on screen, so a long session with dozens of laps will not accumulate rounding errors. Times are shown to a hundredth of a second, which is as precise as a browser stopwatch started by hand can honestly claim to be.
Accuracy and background tabs
The stopwatch measures against a steady clock that is independent of the time of day, so changing your system clock or crossing a daylight-saving boundary cannot add or remove time from a running measurement. Switching tabs stops the display updating but not the measurement; the moment you come back it catches up to the correct value. Refreshing the page keeps a running or paused stopwatch, along with its laps.