Online stopwatch

Press Start (or the space bar) to begin timing. The display shows minutes, seconds and hundredths of a second, and hours once you pass 60 minutes. Press Stop to pause; the time is kept, and Resume continues from where you left off. Reset clears everything, but only while the stopwatch is stopped, so you can't wipe a running time by accident.

The elapsed time also appears in your browser tab title while it runs, so you can keep an eye on it from another tab.

Shortcuts are ignored while you're typing in a text field elsewhere on the page.

Each time you press Lap, the stopwatch records two numbers: the lap time (time since the previous lap) and the total time. The newest lap appears at the top.

With two or more laps, the fastest lap is shown in green and the slowest in red, and the average lap time is shown below the table. That makes it easy to see whether your pace on a track, in a pool or on a training circuit is consistent.

Example: laps at 1:05.20, 2:08.90 and 3:11.40 total give lap times of 1:05.20, 1:03.70 and 1:02.50. The third lap is the fastest, and the average is 1:03.80.

The stopwatch measures time from your device's high-resolution clock rather than counting screen updates, so it stays accurate even if the display briefly stutters or you switch tabs. The display refreshes many times a second; the stored time is exact to the millisecond and shown to the hundredth.

Human reaction time when pressing a button is typically around 0.2 seconds, so for official races, electronic timing is still the standard. For workouts, cooking, presentations, experiments or games, this stopwatch is more than precise enough.

• Running and swimming: time intervals and laps.
• Speeches and presentations: practice staying within your time slot.
• Science class: time experiments and record repeated measurements.
• Board games and quizzes: time each player's turn.
• Productivity: see how long tasks really take.

If you need to count down from a set time instead, use the online timer. For focused work sessions, try the Pomodoro timer. The stopwatch runs entirely in your browser; no data is sent anywhere.

Use the stopwatch when you don't know how long something will take and want to measure it. Use a timer when you know how long you want something to last and want an alarm at the end. Coaches often use both: a stopwatch for lap times and a timer for rest intervals between sets.