How to use the timer
- Tap a length (30 s to 1 h) to start straight away, or type hours, minutes and seconds and press Start (or Enter). Minutes over 59 are fine: 90 minutes becomes 1:30:00.
- Add a label if you like (Quiz, Break, Tea). It shows above the time and in the tab title.
- Press Full screen or F for a projector, a smartboard or a phone on the desk. The buttons fade while the timer runs; move the mouse or tap to bring them back.
- When time is up the alarm rings for up to a minute. Press Stop alarm, Esc, or click the display to silence it. The status line then counts how long ago time ran out, which is handy for a speaker who runs over.
Keyboard shortcuts: Space starts and pauses, R resets, + adds a minute, F toggles full screen and M mutes. Your display, colour, sound and volume are remembered in this browser, and the last time you set is kept for your next visit. Nothing is sent anywhere.
Displays: ring, pie, bar or numbers
Open Display and sound to pick how the time is shown:
- Ring: the digits inside a ring that empties as time passes. A good default on a laptop or phone.
- Pie: a coloured disc that shrinks towards 12 o’clock, the style of the visual timers used in classrooms and workshops. People can see roughly how much time is left from across a room without reading the numbers. The whole disc is always the full length you set.
- Bar: a progress bar under the digits, which suits a wide screen or a stream overlay.
- Numbers only: the largest digits, for reading from the back of a hall.
The colour applies to the ring, the pie and the bar. All five colours stay readable in both the light and dark theme.
Alarm sounds, warning ping and repeat
There are five alarm sounds, all generated in your browser: a digital beep, a chime, a bell, a loud buzzer for a noisy room, and a gentle arpeggio for a library or a sleeping house. Press Test to hear the one you picked at the current volume. Warning ping plays a short, quieter ping 10 seconds to 10 minutes before the end, so people can wrap up before the alarm. Repeat restarts the timer as soon as a round ends, with one ring in between: use it for interval training, practice rounds or a reminder every 20 minutes. Each round is timed from the end of the last one, so rounds don’t drift. Add a Break between rounds and the timer alternates work and break, for example 25 minutes of focus and a 5-minute break for the Pomodoro Technique.
Share result copies a link (or opens your phone’s share menu) that sets up the same timer for someone else: the length, label, display, sound, warning and repeat. It doesn’t start until they press Start. The settings travel in the link itself, after the #, so nothing is stored on a server.
On phones that support it (Android, not iPhone) you can also make the phone vibrate. On a computer, tick Notify me to get a system notification when the timer ends while you are in another tab; the browser asks for permission only when you tick the box.
Why it stays exact
Browsers slow down pages you aren’t looking at: timers in a background tab run at most about once a second, and Chrome can stretch that to once a minute for a tab that has been hidden for a while. A timer that counts ticks falls behind when that happens. This one stores the moment the countdown ends and compares it with your device’s clock on every update, so it shows the right time as soon as you look, and a separate timeout fires the alarm at the end. While it runs, the page asks the browser to keep the screen awake (the Screen Wake Lock API), so a projector or a phone on a stand doesn’t go dark mid-countdown.
Troubleshooting
- No sound: check the sound isn’t set to No sound, the volume slider and your device volume, and that the tab isn’t muted. On a phone, silent mode can mute web pages. Press Test to check.
- The screen went dark: battery saver or Low Power Mode can overrule the page. Plug in, or lengthen the screen timeout.
- On a phone the alarm came late: phones pause pages that are in the background or behind a locked screen. Keep the timer open on screen; the countdown itself is still right when you come back.
- Full screen doesn’t work on iPhone: Safari on iPhone doesn’t let pages go full screen, so the timer fills the browser window instead.
Running a game or a class activity? Pick who goes next with the wheel spinner or roll with the dice roller, then time the round here. Need a plain dark or white screen between rounds? Use the black screen.