How to use the countdown timer
Enter a duration in the Hours, Minutes and Seconds boxes — the readout updates as you type, so you can check the total before you commit. Press Start to begin. Pause freezes the remaining time and pressing Start again resumes from that exact point, so an interruption never costs you seconds. Reset reloads whatever duration is currently in the boxes.
For the intervals people use most often there are one-click pages: the 5 minute timer, the 20 minute timer and the 60 minute timer all start from a preset value.
Why this countdown stays accurate
Simple timers subtract one second every time the browser fires a tick, which quietly loses time whenever the tab is throttled, the device sleeps or the page is busy. This countdown instead records the exact moment it should finish and compares that timestamp with the system clock on every update. The result is that a one-hour countdown ends one hour after you pressed Start, whether or not you kept watching the tab.
The alarm, privacy and offline use
The alarm is a short tone generated by the browser's audio engine — there is no sound file to download and nothing plays until you have pressed Start, which is exactly what modern browsers require. Everything runs inside the page: no account, no data sent anywhere and no record of what you timed. Once the page has loaded it will even finish a countdown with the connection off. To measure elapsed time rather than time remaining, use the stopwatch, and for work-and-break cycles the pomodoro timer switches phases for you.
Frequently asked questions
- How do I set a countdown timer for a specific time?
- Type the number of hours, minutes and seconds into the three boxes and press Start. The readout shows the total in HH:MM:SS before the countdown begins, so you can check it first.
- Does the countdown timer make a sound at zero?
- Yes. When it reaches 00:00:00 the page displays "Time's up!" and plays a short beep. The sound is only prepared after you press Start, so nothing ever autoplays.
- Can I pause and resume the countdown?
- Yes. Pause stores the remaining time and Start continues from that value rather than restarting the whole duration.
- Will the timer keep working if I switch tabs?
- Yes. Because it compares the finish time with the system clock, the remaining time is still correct when you return, even if the browser slowed the tab down while it was hidden.
- Can I set a countdown longer than 24 hours?
- Yes — put the whole duration in the Hours box, for example 48 for two days. The readout keeps counting in HH:MM:SS, so 48 hours starts at 48:00:00 rather than rolling over to a day counter.