Classroom timer
A big, clear countdown for the classroom projector or smartboard. Fullscreen with one key, a loud bell at the end, and presets for the activities teachers run most.
How to use the classroom timer
Press F for fullscreen so the digits fill the board. The bar under the numbers gives younger students a visual sense of time passing, and the sound can be tested before the lesson so it is not a surprise. Use Embed on the alarm page to put a clock on a class website.
Other timers: interval / Tabata timer, Pomodoro, stopwatch, any length.
Questions
Will the alarm ring if I close the tab or the laptop?
No. No website can ring after the browser is closed or the computer sleeps. Keep this tab open, plug in, and the clock keeps the screen awake for you. The Ready-to-ring check under the clock shows what is set up correctly.
Does it work on my phone?
Yes on Android while the tab is open (behind other tabs is fine). On iPhone the page must stay in the foreground because Safari does not let web pages play sound from the background. Add it to the Home Screen for a full-screen bedside clock.
Is it loud enough for heavy sleepers?
Pick Loud buzzer or Siren, set the volume slider to full, and switch on the sums-to-stop option in Settings so the alarm cannot be dismissed half asleep. The sunrise light brightens the screen before the alarm too.
Can I use my own sound?
Yes. In Settings, choose an MP3, WAV or OGG file. It is stored in this browser only and never uploaded. There are also 60 built-in sounds, from a twin-bell alarm clock and a rooster to an air horn and a music box, on the sounds page.
What do the sleep sounds do?
Rain, brown noise, white noise, fan and ocean are generated in the browser and play until the alarm, then fade out as it rings. They keep the tab active through the night.
Does it need an internet connection?
Only to load the page the first time. Alarms, sounds, the sleep calculator and the sunrise math all run on your device, and the page works offline once it has been opened.
Is anything stored or sent?
Alarms and settings are saved in your browser's local storage. Nothing is sent to a server, and there is no account.
Does the classroom timer keep running if I switch tabs?
Yes. It measures time against the device clock, so a background tab still ends on time and rings when it does; on desktop the sound plays from the background too.
Can I use it on a phone?
Yes. Keep the page open; on iPhone it must stay in the foreground to play sound.