Countdown timer
Count down a duration in hours, minutes and seconds with an optional sound alert.
Your inputs
Your result
Ready
00:05:00
How it works
- The timer compares the current device time with its deadline instead of subtracting ticks. Pause preserves the remaining duration.
Assumptions and limitations
Time comes from your device, not a synchronized time server. Keep this page open and the device awake for alarms and timers. Background tabs may delay sound. Nothing is saved after leaving this page.
Sources
- MDN — browser timers and background throttling Sources reviewed: 2026-10-24
