Countdown Timer & Stopwatch

Countdown to a moment, or count off a duration

Switch between two ways to count down. Duration mode takes a plain HH:MM:SS value — or a one-tap preset — and counts to zero; use it for a workout round, a cooking timer or a focus block. Target date mode counts down to an exact calendar moment, which is what you want for a launch, a deadline or New Year's Eve. Either way the value is written into the page URL, so bookmarking the tab or sending the link to a colleague reopens the very same countdown, already running.

Why the remaining time never drifts

The display is recomputed from your device clock on every animation frame rather than by subtracting a fixed amount each tick. That means switching tabs, locking the screen or letting the laptop sleep cannot make the timer fall behind — the moment the page is visible again it shows the correct remaining time. When it reaches zero the clock turns red, a short beep plays, and — if you granted permission with the Notify me button first — a system notification fires even while the tab is in the background.

Stopwatch with laps

The stopwatch counts up to hundredths of a second and records lap splits: each lap shows both the split (time since the previous lap) and the running total. Start, stop and resume as often as you like — the elapsed time accumulates across pauses. Nothing here is uploaded: the timer, the stopwatch and the alarm all run locally in your browser.