15 Minute Timer
Start a 15 minute timer instantly — no sign-up, no setup. Pause, reset, add time or go fullscreen, and get a clear alarm when the 15 minute timer reaches zero.
Quick presets
About the 15 Minute Timer
15:00 on the clock — fifteen minutes of clear, visible time. The 15 minute timer on this page is ready the instant it loads: press Start and the countdown runs, accurate to the second even if you switch tabs, project a slideshow or let the screen sleep. You can pause, add a minute, reset or go fullscreen without leaving the page.
Fifteen minutes — 900 seconds — is a quarter of an hour, which makes the 15 minute timer the natural unit for splitting lessons and meetings. Four 15 minute timer blocks fill an hour with four different activities, and one block is exactly right for sustained independent work before young attention fades.
Everything on this page happens locally in your browser, which keeps the 15 minute timer fast and dependable on old classroom hardware, shared laptops and locked-down school networks. There is nothing to install, no extension to request from an administrator, and no account to create before class. Bookmark the page once and your 15 minute timer is one tab away all year.
How to Use the 15 Minute Timer
Running the 15 minute timer takes three steps:
- 1
Press Start
The 15 minute timer begins counting down immediately. The ring around the digits empties as time passes.
- 2
Pause, add time or reset
Pause the 15 minute timer for interruptions, tap +1:00 when a task needs longer, or reset back to 15:00.
- 3
Go fullscreen
Project the 15 minute timer with the Fullscreen button so everyone in the room can read it from their seat.
- 4
Finish
At 00:00 the 15 minute timer plays your chosen alarm and shows a clear Time’s up message. Restart it for another round.
What Can I Do in Fifteen minutes?
In fifteen minutes a student can write a full short answer response, complete a section of a mock exam or finish a focused study burst. The 15 minute timer is also the standard short-meeting length that keeps agendas tight.
Outside the classroom the same countdown works just as well: time a cooking step, a workout round, a practice session on an instrument or a focused work block. The 15 minute timer does not care why the time matters — it simply makes the remaining time visible until the moment is used up.
Classroom work blocks
Set the 15 minute timer for independent or paired work and take the noise level down with it.
Study sessions
Fifteen minutes of revision followed by a short break — the 15 minute timer is the gentle cousin of the Pomodoro.
Quizzes
A full section of a test fits a 15 minute timer, giving assessments a predictable rhythm.
Short meetings
Stand-ups and check-ins that respect a 15 minute timer end while they are still useful.
Why This 15 Minute Timer Stays Accurate
Browser timers usually count ticks, and browsers pause ticks in background tabs — that is why so many online countdowns drift. This 15 minute timer works differently: pressing Start records the exact finish time, and the display is recomputed from the system clock several times a second. Switch windows, let the machine sleep or mute your screen — the 15 minute timer still ends on the second you set.
While the countdown runs, the browser tab title becomes a live clock, so you can keep an eye on the 15 minute timer from another window or a second monitor. When the alarm finally sounds, the page switches to a clear finished state with a restart button — no auto-looping, so the 15 minute timer never restarts itself without a decision from you.
- No drift — the 15 minute timer is anchored to the finish timestamp, not to ticks.
- Works offline once loaded — the countdown never needs the network.
- Fullscreen mode turns any screen into a readable 15 minute timer display for the whole room.
- Alarm sounds — bell, chime or beep — or full mute for silent settings.
15 Minute Timer Tips
- Press Space to start or pause the 15 minute timer, R to reset and F for fullscreen.
- Choose your alarm sound before the lesson — the choice is remembered on this device.
- Pair the 15 minute timer with a visible routine: same sound, same stop, every time.
- Need a different length? Use Edit time or jump to any preset from the list below.
- Refresh the page at any point to bring the 15 minute timer back to 15:00 and start over clean.
15 Minute Timer FAQ
How do I set a 15 minute timer?
Open this page and press Start — the 15 minute timer is preloaded with 15:00 and begins immediately, no setup or sign-up needed.
Does the 15 minute timer still count when I change tabs?
Yes. The countdown stores its finish time and recomputes the remaining seconds on every update, so background tabs and sleep mode cannot make it drift.
Is this 15 minute timer free?
Yes — it is completely free, works without an account, and runs entirely in your browser on any device.
Can I change the 15 minute timer duration?
Yes. Use Edit time to set any hours, minutes and seconds, or press Reset to come back to 15:00.
Will the 15 minute timer work on a projector?
Yes. Fullscreen mode fills the screen with the digits — large enough to read from the back of a classroom.
Does the 15 minute timer make a sound at zero?
It plays your chosen alarm — bell, chime or beep — at 00:00, or stays muted if you prefer a silent visual finish.
Sources and technical references
The engine on this page updates the remaining time roughly five times per second (every 200 ms), the stopwatch resolves time to 10 milliseconds, and every duration accepts up to 24 hours. The specifications behind these claims are published openly:
- Web Audio API — MDN Web Docs
- Fullscreen API — MDN Web Docs
- performance.now() — MDN Web Docs
- High Resolution Time Level 3 — W3C
- HTML Standard: timers and user prompts — WHATWG
Last updated: 2026-09-28 · Maintained by the Classroom Timer team