Online timer
Set any countdown, hear an alarm, and run it fullscreen.
05:00
Ready
Press Esc to exit
Keep this tab open and the device awake. Background or locked-screen alarms are not guaranteed.
Presets
Custom time
Alarm
Other versions
-
1 minute timer
One minute, one press, and an alarm you can hear. -
5 minute timer
Five minutes with an alarm, in the tab or fullscreen. -
10 minute timer
Ten minutes on screen, with the alarm you choose. -
15 minute timer
Fifteen minutes, an alarm, and nothing to set up. -
30 minute timer
Half an hour, counted down where you can see it. -
1 hour timer
Sixty minutes, counted down and announced.
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Color screen
Pick any color and fill the whole screen, with brightness and an optional clock.
Set a duration from one second to 24 hours, choose an alarm and press Start. The countdown and remaining time in the tab title run in your browser. Pause holds the remaining time; Reset returns to the chosen duration. Test the sound before relying on it. Keep the page open and the device awake: browsers can delay alarms in background tabs, suspend audio or stop work when a phone locks. For an important reminder, use your device's alarm instead.
How to use
- Pick a preset or type hours, minutes and seconds in the fields.
- Press Start. The countdown runs and the tab title shows the time left.
- Choose an alarm sound and set the volume, or press Test sound to hear it first.
- Press Go fullscreen to fill the screen, and Esc to come back.
- Press Reset to return to the set time, or Pause to hold it where it is.
What it handles
- Six duration presets, custom hours/minutes/seconds and a maximum of 24 hours.
- The display uses elapsed time, not a count of interval callbacks; ordinary background throttling does not accumulate tick drift.
- Three synthesized Web Audio sounds, a volume control and a sound-test button; no alarm recording is downloaded.
- Repeat requests repeated sound while the page can run; mute, sleep and browser suspension can prevent it.
- The timer requests a screen wake lock while running, releases it on pause/reset and retries on return to a visible tab.
FAQ
Will the alarm ring when my phone is locked?
It is not guaranteed. The browser or operating system can suspend the tab, its clock or audio when the device sleeps or locks. Background alarms can arrive late or not play. Keep the tab visible for this timer; use a system alarm for anything time-critical.
Why should I test the sound first?
The browser synthesizes the beep, chime or bell using Web Audio. Playback depends on browser permission, tab muting and device volume. Press Test sound and check the output you will use. Starting the countdown requests audio playback, but cannot override mute or a suspended device.
Which durations and inputs are supported?
The range is one second to 24 hours. Hours, minutes and seconds are added, so 90 in the seconds field means one minute and thirty seconds; values above a day are capped. Use whole non-negative numbers, not decimals. Editing a field resets the countdown rather than modifying a running timer.
What happens offline or when I share the link?
An already-loaded page can count and generate sound without a connection, but reopening offline is not guaranteed. The duration can be included as a t parameter; opening a shared link sends that URL to the site and starts a fresh idle timer, not a synchronized session. Preferences are stored in this browser when available.
Updated