A period timer you can share with a substitute
Send the page URL. They get 45:00 without hunting presets. For stations, use the 15 or 20 minute timer pages. For a teacher-oriented embed pack, open Timer for Teachers.
45:00
45:00
Up next
While running, tap a preset to queue up to 3 timers.
Presets
One tap: skin, backdrop, and motion.
Ready
00:30
Ember focus
D · display mode
Time’s up!
Photo gallery
Tap a photo to set the stage backdrop. Instant looks still control skin and motion.
Timer settings
Set a custom duration and title, then fine-tune look and alarm if you need to.
Timer setup
Appearance
Looks on the stage already set the scene. Here: digit style, photo gallery / custom photo, and display blur.
Digit style
Custom photo
Sound
Volume
Saved setups
Favorites
No favorites yet. Set up a timer you like, then tap "Save current".
History
No completed timers yet. Finish a countdown to see it here.
More timers
More durations or a short countdown to a date — pick a pane.
Durations
Seconds
Hours
Countdown
Custom date & time
Day of week
Time of day
Date & holiday countdowns
Live days–hours–minutes–seconds to any date or holiday.
Learn more
Period countdown
Forty-five minutes on the board
The classroom timer opens at 45:00 — a common period length. Put it on the projector, use sleep mode so only the countdown remains, and start when the bell rings.
Teachers need a clock that is readable from the back row and does not depend on a phone in a pocket. This is the full timer: queue a 5-minute cleanup, embed a widget on Google Sites, or copy a link for a substitute. No class roster, no sign-in.
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01
Start the period at 45:00
Press Start at the bell. Fullscreen for the board. Queue a short timer for pack-up if you always need a two-minute warning.
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02
Start the countdown
Press Start or Space. Progress updates on a circular dial, and the face shows when the timer ends. Pause anytime, add +1 min, queue another timer, or go fullscreen / sleep for a distraction-free display. The tab title shows remaining time while you work elsewhere.
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03
Hear the alert & keep going
When time is up, stop the alarm with one tap. Start the next queued timer, review local history, export CSV, or copy a shareable link. A refresh restores an in-progress countdown on this device.
What you get
- Presets & quick lengths Jump to common seconds, minutes, and hours, or named timers like study and classroom. The Countdown pane still offers weekdays, times of day, and a custom datetime — holiday countdowns are on the Online Countdown tool.
- Background-tab accuracy Countdown uses deadline math so it stays correct when the browser throttles hidden tabs.
- Sounds, notifications & wake lock Choose alert sounds and ring length, get a desktop notification when finished, and keep the screen awake while running.
- Fullscreen & sleep mode Go fullscreen for a large dial display, or sleep to dim the whole page so only the countdown stays visible.
- Up-next queue While a timer is running, tap presets to queue up to three countdowns and start the next when you are ready.
- Embed widget Drop a compact countdown on your site with custom colors, size, skin, and default duration.
Frequently asked questions
Setting the dial, presets, alerts, and embeds — quick answers.
Can I show this classroom timer on a projector?
Yes. Fullscreen or display mode enlarges the digits. Sleep mode hides chrome so students only see remaining time.
Does the classroom timer need student accounts?
No. It runs in the browser on the teacher machine or an embed on a class page. Nothing is stored in a school login.
Our periods are 50 minutes. Can I change it?
Tap the dial to set 50:00, or start here and add +1 min five times. There is no 50-minute SEO page on purpose — we keep duration URLs to a short list.
How do I embed a classroom timer?
Use the embed builder on this page, or copy a ready iframe from the Timer for Teachers pack. Timing stays in the visitor’s browser.