Collaborative Timer

One timer. Every screen in sync.

Host a countdown, stopwatch, or Pomodoro from one device and share the QR code. Students, teammates, or friends join on their phones and see the exact same clock — if the host pauses it, everyone pauses.

How a collaborative timer works

  1. Create the session and add a countdown, stopwatch, or Pomodoro timer.
  2. Show the QR code, share the join link, or read out the short room code.
  3. Everyone opens the link and sees the same synchronized timer on their own screen.
  4. Start, pause, and reset from the host — every connected device updates at once, and a chime plays when a timer finishes.

Great for groups

  • Classrooms — timed reading, quizzes, games, and breaks
  • Meetings — agenda slots and one-person-one-minute turns
  • Workouts — rounds, rests, and intervals synced to every phone
  • Cooking — timers for every dish on one shared screen

Five tools in one

Countdown — set a time, everyone counts together

Stopwatch — a shared elapsed clock for races or tests

Pomodoro — work and break cycles that auto-alternate

Multiple timers — run several at once

Sound alerts — a chime on every device when a phase ends

Privacy and connection limits

The host browser holds the shared timer state in memory; nothing is uploaded or stored on a server.

To let two devices find each other, this static tool uses the free PeerJS Cloud signaling service for connection setup only. After that, timer data moves over WebRTC data channels. Some restrictive networks may require relay infrastructure, and the session ends when the host closes its tab. Do not rely on it for emergency or safety-critical timing.

Frequently asked questions

Do participants need an app or account?

No. They scan the QR code or open the link in any modern browser.

If the host pauses the timer, does everyone pause?

Yes. The host owns the state, so every connected screen pauses, resumes, and resets at the same moment.

Can I run more than one timer?

Yes. Add as many countdowns, stopwatches, or Pomodoros as you like in the host view.

What if the host closes their tab?

The session ends and everyone disconnects. Keep the host tab open for the whole class, meeting, or workout.

More free tools for groups

Cast live questions to phones with Live audience voting, run a quiz night with Couch Trivia, or play cards together with Couch Poker.