Stopwatch

This free stopwatch times how long something takes, in the browser. Press Start when you want to begin, Pause to freeze the total, Lap to snapshot the elapsed reading, and Reset to return to 00:00:00.00. You do not need an account.

The face reads hours:minutes:seconds.hundredths — HH:MM:SS.cc. Space starts or pauses, L records a lap, and Ctrl+R resets. Fullscreen enlarges the widget. This is a browser timer, not a certified race clock.

What a stopwatch measures

A stopwatch measures elapsed time: how much clock time passed after you pressed Start. It does not answer what time it is now, and it does not shift a calendar date. For adding hours and minutes onto a starting clock, use the Time Calculator. For the number of hours between two date-times, use the Hours Calculator.

How to use Start, Pause, Lap, and Reset

Start begins counting from whatever total is already on the face — zero when you first open the page, or the paused value if you stopped earlier. Pause freezes that total so you can resume without losing it. Lap writes the current elapsed reading into the list while the clock keeps running. Reset sets the display back to 00:00:00.00 and clears every lap. Lap stays disabled while the stopwatch is still at zero and not running.

Keyboard shortcuts and fullscreen

Space toggles Start and Pause. L records a lap. Ctrl+R resets. Those shortcuts skip when you are typing in an editable field. Fullscreen enlarges the stopwatch card so the readout is easier to read across a room; Esc exits fullscreen. The same Start, Pause, Lap, and Reset buttons remain in fullscreen.

Reading HH:MM:SS.cc hundredths

The readout is hours:minutes:seconds.hundredths, written HH:MM:SS.cc. 00:01:30.40 is one minute, thirty seconds, and forty hundredths. A hundredth is 1/100 of a second, so the last two digits are .cc, not three-digit milliseconds. 00:00:00.00 is ready; hours appear once the total crosses sixty minutes.

Pause vs reset, and what a lap records

Pause holds the accumulated total so you can continue later. Reset discards the total and the lap list. Each lap is a snapshot of elapsed time at that instant — the same HH:MM:SS.cc value showing on the face — not the gap between two taps. If you lap at 00:01:00.00 and again at 00:02:05.40, both numbers are running totals, not a 1:05.40 split.

Stopwatch vs countdown and calendar time

This page counts up from zero. A countdown counts down toward a target. The How Long Until Calculator shows days, hours, and minutes remaining until a date-time. The Event Countdown Calculator subtracts one day-number from another. The Date Calculator adds or subtracts whole days on the calendar. For running, elapsed time and distance become pace on the Pace Calculator; the How to Calculate Running Pace tutorial uses the same ratio.

Worked example: steeping tea for 2:05.40

Start the stopwatch when you pour the water. At 00:01:00.00 tap Lap to mark one minute. At 00:02:05.40 press Pause when the bag comes out. The face reads 00:02:05.40 — two minutes, five seconds, and forty hundredths. The lap list shows two snapshots of elapsed time, 00:01:00.00 and 00:02:05.40, not the 1:05.40 between them. Reset would wipe the 2:05.40 total and both laps.

\[ 00:02:05.40 = 2\,\mathrm{min} + 5.40\,\mathrm{s} \]

Frequently asked questions

References

• Wikipedia — Stopwatch

Assumptions and limitations

This stopwatch is a browser timer, not official race timing. Do not use it for certified results, exam invigilation records, or any clock that must meet a sporting or laboratory standard.