LESS WATCHING THE CLOCK. MORE TIME TO LEARN.

Classroom timer.

A clear, visual countdown for the whole room. Ready for your next lesson.

CLASSROOM COUNTDOWN

Minimal elegance

Use the alarm and timer dials, or the controls below.

Weather · Choose a city · Change city

Temperature

Choose a city to show current weather.

Weather estimates by Open-Meteo · refreshes every 15 minutes.

On first visit, a city is suggested from your browser’s time zone. City searches are sent to Open-Meteo. Your selected city and units are saved in this browser. Privacy

Weather is an estimate for general information and may differ at your location. For safety, travel or emergency decisions, consult official weather services.

Clock details

Smooth second hand

Choose your weather city to load moon data.

Moon data: MET Norway (CC BY 4.0). Phase names, approximate illumination and diagram are derived from its phase angle. The diagram mirrors by hemisphere; sky tilt varies. Rise/set events may fall on an adjacent date.

SOMETHING TO LOOK FORWARD TO

Set your next alarm.

Keep screen awake Off

Ready when you are.

Keep this tab open and your device awake. Browser alarms cannot wake a sleeping device. Learn more ↗

A place for every moment.

Simple tools. No account needed.

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Time for the whole room ↗

A big, visual classroom timer for lessons, transitions and group work.

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Make room for focus ↗

Settle into a work session, then give yourself a proper break.

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Around the clock, worldwide ↗

See the time in New York, London, Tokyo and beyond.

BEFORE THE ROOM FILLS UP

How to use a classroom timer on a projector

Set up the countdown on the computer connected to your classroom display. Before the lesson, run a short practice timer so you can check the screen, the sound and the controls in the room where you will use them.

Set up the display

Connect and open the page. Connect your computer to the projector or classroom screen, then open this classroom timer. Show the browser on that display. If you extend your desktop, move the browser window onto the classroom screen before opening fullscreen.
Choose the duration. In the Timer tab, select 5, 10 or 15 minutes, or enter your own duration in Minutes. Pick the duration before starting: selecting a preset replaces the current countdown.
Test the sound. Open the Alarm tab and select Test sound. Check that you hear it through the intended speakers. Look for muted browser tabs, low volume or a connected headset if you do not. Return to Timer afterward. See the sound setup guide for more checks.
Start, then open fullscreen. Select Start timer, then Fullscreen above the display. The controls disappear and the countdown fills the view. Check it from the back of the room: students should be able to read the numbers as well as see the shrinking disk. Adjust the display size or room lighting if necessary.
Keep the computer available. Try Keep screen awake before entering fullscreen if your browser supports it, and check its status. Keep the device awake and plugged in when appropriate. Closing the laptop or putting the device to sleep can stop alerts; screen wake lock cannot prevent every system restriction. Read the browser reliability guide.

Pause, resume and reset

For an interruption, press Escape to leave fullscreen, then select Pause. Select Resume when everyone is ready and open Fullscreen again. Reset stops the countdown and returns it to the chosen duration. You can then choose a different duration for the next activity.

When time expires, dismiss the completion message. A chime plays only if browser audio is enabled. If you reload the page, the remaining time is restored when browser storage is available, but test the sound again before relying on an alert.

Example: a ten-minute group task

This is a starting example you can adapt to your class, rather than a fixed teaching formula.

First minute: explain the task, the roles and what each group will share.
Next eight minutes: let groups work. Give a spoken reminder when there is one minute of work left.
Final minute: invite a brief response or ask students to record their next step.

The countdown marks the total ten minutes; it does not announce these three stages automatically. You provide the cues. Pause or allow more time when students need it.

Use the 10-minute preset above, or open the standalone 10-minute timer for a simple numerical countdown.

A quick check before class

Try a one-minute countdown, enter fullscreen, leave it with Escape, pause, resume and reset. Then let a short countdown finish and confirm that you can hear the chime. Ask a colleague or teacher to try the workflow with your display before depending on it during a lesson.

Using a phone?

The same Timer controls fit a phone screen. Keep the page in the foreground and test the actual connection if you cast or mirror it to a display. A locked phone may restrict the browser, and fullscreen availability varies. A phone preview alone does not establish that a particular casting setup will work.

Desktop classroom timer showing a ten-minute visual disk with duration, start and reset controls. — Desktop setup: choose the duration before starting and entering fullscreen.

Phone view of the classroom timer showing its ten-minute visual disk and timer controls. — Phone view: check the controls and keep the browser available.

More practical guides

All guides · Timer durations · Printable planner

Audio, background tabs, and screen wake lock

Use Test sound after opening or reloading this tool. That click activates browser audio, but you must also confirm the intended speakers are audible. A connected headset, muted tab, or changed Bluetooth output can make an otherwise working timer silent. Browser audio permission is not a guarantee that a future alert will run while the device is asleep.

On desktop Chrome, Settings → Performance → Always keep these sites active lets you add alarmclock.live to reduce Memory Saver deactivation. Energy Saver can also pause eligible background work. Keep the tool visible, and consider plugging in the device for a session. These settings are not available in the same form on mobile Chrome. See Chrome's performance documentation for the current controls.

In Safari, test audio on the actual device and review the site's sound or autoplay preferences if playback is blocked. Keeping a tab open is not the same as keeping it running: switching apps or locking a mobile screen can suspend execution. There is no website switch that guarantees an iPhone or iPad will execute a timer in the background. Use a native timer when you need to lock the device or leave the browser.

Keep screen awake requests the browser's screen wake lock while supported and active. Check the displayed status rather than assuming the request succeeded. A lock can be released when the page becomes hidden or the battery is low; it cannot override closing a laptop, turning off the device, or system sleep. The countdown uses an end time to correct itself when execution resumes, but a delayed callback cannot deliver a sound retroactively at the missed instant. See screen wake-lock behavior and our full reliability guide.

Tools for your daily routine

Wake-up alarm · Meditation timer · Sleep calculator · Pomodoro timer · Classroom timer

Each tool includes setup instructions and an explanation of what a browser can and cannot do.