Classroom Timer

A countdown timer that shows the time left in large numbers. Put it on the classroom or meeting-room screen so everyone can see how much time is left for an activity, a talk or a break.

How to use

1. Press one of the quick buttons from "1 min" to "30 min", or type the time in the "min" and "sec" fields.
2. Press "Start" to begin the countdown, and press it again to pause.
3. Press "+1 min" to add time, or "Reset" to go back to the time you set.
4. Press "Full screen" to make the numbers fill the screen.

How it works

• The color changes when 10% or less of the time is left. At zero the screen changes, and an alarm sounds if "Play a sound when time is up" is on.
• While the timer runs, the screen is kept awake and the time left also appears in the browser tab title.
• The time you chose and the sound setting are saved in this browser and come back the next time.

Questions and answers

Are there keyboard shortcuts?

Space starts and pauses, R resets, F switches to full screen and + adds a minute.

Does the alarm still sound if I switch to another tab?

Yes. The timer counts toward a fixed end time, so it stays correct in the background and the alarm sounds at the end. The computer's sound must be on.

What is the longest time I can set?

Up to 999 minutes and 59 seconds. For 1 hour 30 minutes, enter 90 in "min".