Classroom timer
A big, readable countdown for the projector or your laptop: one-tap presets from 1 to 60 minutes, custom durations, pause and resume, full-screen mode and an optional beep when time is up.
Activity
Timer runs entirely on this device — no network calls are made.
How to use
- Pick a preset (1, 5, 10, 15, 20, 30, 45 or 60 minutes) or enter a custom duration.
- Optionally label the timer — Activity, Break or Transition — and turn the end sound on or off.
- Press Start; Pause and Resume keep the remaining time exact.
- Use Full screen to project it for the class, and Reset to run it again.
Private by design: this tool runs entirely in your browser — no account, no AI, and nothing you type is sent to a server.
Frequently asked questions
Will the timer drift if I switch tabs?
No. The timer counts against the target timestamp rather than ticking blindly, so background tabs, slow frames and device sleep don't add or lose time.
Where does the end sound come from?
From the browser itself (Web Audio) — no audio file is downloaded, so it works offline and adds no requests.
Does full screen work on a projector?
Yes — Full screen hides everything except the countdown, ideal for a classroom display. Press Esc (or tap) to leave full screen.
Does the timer need the internet?
No. Once the page has loaded, the timer runs entirely on the device — no API, no AI, no network calls.