Classroom Timer
A clear countdown for the whole room. Set an activity, choose a sound, and give everyone a little time.
Set. Start. Take a breath.
Extra time applies to this session only.
Pause and reset to change the start time.
Sound & display Make it work for you
Press Test sound to check your volume before starting.
Keep this page open. Sound may be delayed or unavailable if your device locks or your browser suspends the page.
Time everyone can follow.
Add an activity label such as “Reading time”, “Group discussion” or “Time to pack up”. Open full screen to make the numbers larger on your projector or display.
Keep the progress ring for a visual sense of time, or switch it off for numbers only. Choose Sound off for a quiet ending: the timer still shows a static “Time’s up” message. No flashing, confetti or ads.
A few timely answers.
Can the class use it without sound?
Yes. Choose Sound off. At zero, the large numbers and the text “Time’s up” make the ending clear without relying only on color.
How do I remove the ring?
Uncheck Show progress ring beneath the timer. The numerical countdown remains visible in normal and full screen views.
Can I display the current activity?
Yes. Enter a short activity label, up to 60 characters. It appears above the numbers and is saved with this tab’s session for reload recovery.
Will the alarm work if I close the app?
No. Keep this page open. A locked device, suspended browser or muted device may delay or prevent sound. A home-screen installation is not a background alarm service. Use Test sound to check before relying on it.
Does the countdown continue in another tab?
The timer compares the current time with its saved end time, so delayed screen updates do not simply lose seconds. When you return, it calculates the remaining time again. Your browser may still delay the alarm.
Can I recover a timer after reloading?
On the same page and tab, a reload restores your saved session when browser storage is available. If it already ended, you see the result without an automatic alarm. A fresh visit starts with that page’s default. Separate tabs keep separate active sessions.
What if I change my computer’s clock?
The timer uses your system clock for its end time and reload recovery. Moving the clock forward can finish the timer early; moving it backward can extend it, with the visible remaining time capped at the session duration. It is not a certified timing instrument.
Does full screen work on my phone?
When supported, Full screen expands the timer. Otherwise a browser-window view is used and browser bars may remain visible. Use Exit full screen or Escape to return.
What is saved on my device?
Active sessions stay in this tab’s session storage. Sound, volume, theme and Pomodoro settings are saved locally when storage is available. Offline website files are cached in your browser. There are no accounts or analytics scripts.