Big Timer — Free full-screen countdown timer and stopwatch

A big, simple timer for anything.

Big Timer is a free, full-screen countdown timer and stopwatch built for cooking, workouts, studying, meetings, exams, classrooms, and live streams.

How to use

  1. Step 1

    Set a time

    Type hours, minutes, and seconds, or tap a preset like 5 or 25 minutes. Add an optional label such as Pasta or Exam.

  2. Step 2

    Start and adjust

    Press Start or the Space bar. Add or subtract a minute on the fly, and pause or reset any time.

  3. Step 3

    Go full screen

    Press the full-screen button or F to fill the display — ideal for classrooms, projectors, and streams.

Accurate and private by design

Every countdown is measured from a fixed end time rather than by decrementing a number each second, so background tabs, device sleep, and delayed frames never cause drift. Everything runs locally in your browser — your timers and preferences stay on your device and are never uploaded.

Frequently asked questions

Will the timer work in a background tab?
Yes. Time is calculated from timestamps, not by counting ticks, so switching tabs or minimizing the window will not slow it down. When you return, the display corrects itself instantly and the alarm still fires.
Will it survive a page refresh?
Yes. A running countdown stores its target end time locally, so a refresh restores the exact remaining time. If a timer finished while the page was closed, it reopens in the completed state without replaying the alarm.
Why did the browser block the alarm?
Browsers only allow sound after you interact with the page. Once you start a timer or press Test sound, audio is unlocked for the session. If it is still muted, check your device volume or the Silent completion setting.
Does it keep my screen awake?
When your browser supports the Screen Wake Lock API, Big Timer keeps the screen on while a timer or stopwatch is running and releases it as soon as you stop. If the API is unavailable, everything else still works.
Is any timer data uploaded?
No. Big Timer runs entirely in your browser. Your durations, labels, laps, and preferences are stored locally on your device and never sent to a server. There is no account and no tracking.