Countdown Timer

Start a countdown

1. Enter hours, minutes and seconds, from one second to 99:59:59. Minutes and seconds must each be below 60; blank or all-zero fields cannot start a timer.
2. If you want a short finish cue, turn on sound and use Test sound. Then select Start. Sound is optional and never holds up the visual countdown.
3. Use Pause and Resume for an interruption. Reset stops the run and restores its full chosen duration without starting it. Start again repeats a finished interval.

Read the timer and its states

The large display is hours, minutes and seconds remaining. A positive fraction of a second is shown as a whole remaining second, so 1 millisecond still reads 00:00:01. Finished is 00:00:00; this display precision is not an accuracy guarantee.

The countdown uses a deadline on your device clock rather than counting browser callbacks. Delayed updates catch up to that deadline. Sleep and hidden-tab time are included when the page can run again, but clock adjustments can shorten or extend the interval.

Pause freezes the exact remaining time, including a partial second. Resume creates a new deadline from that remainder; time spent intentionally paused does not count. Reset restores the full interval, while Start again also starts a new run.

Duration fields are locked while running or paused. Reset before changing them. After completion, editing a duration stops any cue and prepares a new timer. No action on a field starts it automatically.

Useful timing examples

For a two-minute presentation practice, enter 0 hours, 2 minutes and 0 seconds. After 12.4 seconds on the device clock, 107.6 seconds remain and the display reads 00:01:48.

If you pause with 99.75 seconds left, the display reads 00:01:40. After resuming and letting another 20 seconds pass, 79.75 seconds remain, shown as 00:01:20. Paused time is excluded.

If a five-second timer is discovered more than two seconds after its deadline, it shows Finished without a late cue. Returning from a hidden page also reconciles silently; a completion alarm is not queued for your return.

Browser and sound limits

Use this page for one duration countdown. It does not provide a stopwatch, calendar alarm, repeating schedule, background notification or guarantee of delivery while a device sleeps or the page is closed, frozen or discarded.

Changing the device clock can move the remaining time backwards or finish the timer early. A backward jump is capped at the current running segment’s starting remainder, but this cannot repair the elapsed time. A finished timer does not restart when the clock changes.

Sound is off until you select it. Browser permission, a suspended audio context, device mute and volume can prevent hearing it. A successful test requests a short three-pulse cue; it does not establish reliable future playback. Visible completion works without sound.

Reload, discard or a new document loses this timer; there is no saved history. Restoration of the same live page may retain it and reconcile its deadline. Language-only label updates do not reset an otherwise mounted timer.

A timer without saved history

The tool adds no duration-bearing requests, saved timer history, input-bearing links or microphone access. Timing and the optional generated tone use this page. Existing site services and browser extensions are outside a universal privacy or erasure promise.