How to use the Classroom Timer
- Pick a time. Click a preset, press a number key (5 sets five minutes), or click the digits and type any time.
- Start it. Press Space or the Start button. Press it again to pause.
- Show it to the class. Press F to present full screen. The controls fade away until you move the mouse.
- Hear the end. Choose bells, a chime, a gong, a buzzer or silence in Settings. The display flashes when time is up.
Classroom ideas
- Use the pie display with younger pupils: they can see how much time is left without reading numbers.
- Give transitions a time limit — “tidy up before the timer ends” — and add a minute with + if they need it.
- Run timed writing sprints, then let pairs swap and peer-review for the next round.
- Put the timer on the Classroom Board next to the noise meter and today’s instructions.
Keyboard shortcuts
| 1 – 9 | Set 1 to 9 minutes |
| 0 | Set 10 minutes |
| + | Add a minute |
| − | Take away a minute (when stopped) |
| E | Type a time |
| F | Present full screen |
Frequently asked questions
Will the alarm ring if I switch to another tab or window?
Yes. The alarm is scheduled on the browser’s audio clock as soon as the timer starts, so it rings on time even when the tab is in the background. Keep the browser window open and the sound on.
Does the timer keep going if I reload the page?
Yes. The timer stores when it should end, not a counter, so a reload, a closed lid or a busy computer cannot make it drift. It picks up where it should be.
How do I make it show on the projector without the menus?
Press F or click Present. The timer fills the screen and the controls hide until you move the mouse. Press Esc to leave.
Can I turn the sound off?
Choose “No sound” under Sound at the end, or use the Sound button at the top to mute the whole site.
What is the longest time I can set?
Up to 99 hours, 59 minutes and 59 seconds. Click the digits to type hours, minutes and seconds.
Updated October 31, 2026 · Free to use in any classroom, no account needed.