Stopwatch and countdown timer
A stopwatch with laps and a countdown timer, running in your browser tab.
How it works
A stopwatch with lap times and a countdown timer. Both keep time against the system clock rather than by counting animation frames, so they stay accurate even when the browser throttles a background tab — which is where most in-page timers quietly lose seconds.
The countdown will alert you when it finishes if the tab is still open. Browsers suspend audio in tabs that have never been interacted with, so start the timer by clicking rather than by keyboard shortcut if you need the sound.
This tool runs entirely in your browser. Nothing you enter is sent to a server, logged or stored, and the page keeps working with the network disconnected.
Common questions
- Does the timer keep running if I switch tabs?
- Yes. It calculates elapsed time from the system clock rather than counting frames, so background throttling does not make it drift.
- Will it work offline?
- Once the page has loaded, yes. Everything runs locally with no network requests.
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