Stopwatch
A precise on-screen stopwatch with laps and a fullscreen display for events, speakers and classrooms.
Ready.
Keyboard shortcuts
- Space — Start, pause or resume
- L — Record a lap while running
- R — Arm reset (press again, or click Confirm, to reset)
- F — Enter or exit fullscreen
Laps
No laps recorded yet. Laps become available once the stopwatch is running.
How this tool works
Start begins counting from zero. Pause freezes the display without losing the time already recorded, and Resume continues from exactly where you paused.
Lap records a split — the time since the previous lap, or since the start for the first lap — alongside the running total. Laps are listed newest first so the most recent one is always easiest to find.
The stopwatch reads your device's clock rather than counting fixed-length ticks, so switching tabs, a slow device, or a throttled background window never loses or double-counts the calculated elapsed time. The display itself is different: it doesn't visibly update while the tab is hidden or throttled — it freezes and then catches up to the correct elapsed time the moment it renders again.
Fullscreen mode enlarges the display for a room: speakers, classrooms, workshops and sports timing. It uses your browser's fullscreen feature where available; if that isn't supported, the large-display view still works without going edge-to-edge.
This page has to stay open to keep timing. The elapsed time, laps and any in-progress timer setup are not retained after a reload — closing or reloading the tab always resets it to zero. Your fullscreen theme and size choice are the one thing saved, in your browser's local storage, so that preference carries over to your next visit.
Frequently asked questions
Does switching tabs or minimizing the browser lose time?
The calculated elapsed time doesn't — it's based on your device's clock, not a repeating timer, so it stays correct even after the tab was inactive or backgrounded. The display itself is different: it doesn't visibly update while the tab is hidden or throttled, it just freezes, then catches up to the correct time the moment it's visible again.
What if my device fully goes to sleep, like closing a laptop lid?
That's different from switching tabs and isn't guaranteed. A full system sleep can pause the browser entirely, and how much of that time (if any) is reflected when it wakes depends on your operating system and browser, not this page. If accurate timing across a real sleep matters, keep the device awake — fullscreen mode's wake lock helps where it's supported, but check the on-page note, since it isn't available everywhere.
Will my screen stay awake while it's running?
Many modern desktop and Android browsers keep the screen on once you start the stopwatch. Support varies by browser — notably older iOS Safari versions — so treat it as a convenience, not a guarantee, and check the on-page note if it matters for your use.
Can I use this as a countdown timer?
Not directly — this tool only counts up. Use the Countdown Timer for a set duration that counts down to zero with a fullscreen speaker/event display and an end-of-time alert.
Is the time saved if I close the page?
The elapsed time and laps are not — closing or reloading the page always resets it to zero. Only your fullscreen theme and size choice is saved, in your browser's local storage, so that one preference carries over between visits.