Stopwatch

How this online stopwatch works

Press Start and the stopwatch counts up in hours, minutes, seconds and tenths of a second. Press Stop to pause and Start again to resume from where you left off. Split records the current time without stopping the clock, and shows the lap time since the previous split next to it. Reset clears everything back to zero. Timing uses your device's high-resolution clock and is refreshed on every screen frame, so it stays accurate for hours and never drifts, even if you switch to another tab and come back.

Fullscreen stopwatch for any display

Click Fullscreen or press F to turn the stopwatch into a huge clock that fills the entire screen. The digits scale to fit whatever display you are on: a 16:9 monitor or TV, a projector, an ultrawide, a tablet or a phone held in portrait. The controls fade out after a few seconds and reappear when you move the mouse or tap the screen. This makes it ideal as a classroom timer, a gym or workout clock, a speech and presentation timer, a rehearsal clock, or a countdown-free timer for exams and meetings that everyone in the room can read. Press Esc or F again to exit.

Add a ding every few seconds or minutes

By default a soft bell sounds every 10 minutes. Change the interval under Add a ding every, for example every 30 seconds or every 5 minutes, or untick it to turn the ding off. While the stopwatch is running you will hear a soft bell each time that interval passes, and the display flashes briefly. This lets you keep track of elapsed time without looking at the clock: use it for interval training, timed practice sessions, pomodoro-style work blocks, presentation pacing, or to remind yourself to switch tasks. The ding is generated in your browser so it works offline and needs no downloads. Your interval setting is remembered the next time you visit.

Keeps your screen awake

While the stopwatch is running, or whenever it is in fullscreen mode, the page asks your device to keep the display on so the screensaver or auto-lock will not interrupt it. This works in current versions of Chrome, Edge, Safari and Firefox on desktop and mobile. On browsers without this feature the stopwatch keeps counting correctly in the background; only the screen may dim.

Keyboard shortcuts

• Space or Enter: start or stop
• S: record a split
• R: reset
• F: enter or exit fullscreen
• Esc: exit fullscreen