15 Minute Timer
Ready at 15:00. Press Start, then use optional checkpoints if you want an earlier warning.
15-minute countdown
Starts when you press Start.
Ready for 15 minutes.
One tap starts the full 15 minutes
The initial state is always 15:00. The display also shows the expected finish time after you start, which makes it easier to coordinate a study sprint, classroom activity, meeting segment, workout, or break without calculating the clock time yourself.
Checkpoint alerts, not only an alarm at zero
A normal countdown speaks only when the time is gone. This timer can also mark 10, 5, and 1 minute remaining. Select only the checkpoints you need. Each cue fires once, even if the page redraws, is paused, or is restored.
Visual-only is the quiet default. Sound requires a user interaction because browsers restrict automatic audio. Test the selected sound before relying on it, and keep the visible countdown available as the fallback.
How reload recovery works
While running, the tool stores the target finish timestamp on this device. Every update compares that timestamp with the current clock, so a delayed browser callback does not accumulate into timer drift. Reloading reconstructs the remaining time from the same finish timestamp.
If the deadline passed while the page was unavailable, the display changes to 00:00 and reports how long ago it ended. This does not turn a browser page into an operating-system alarm: sleep, battery restrictions, muted audio, or closing the browser can still prevent a sound at the exact moment.
Controls and shortcuts
- Space: start, pause, or resume while you are not typing in a control.
- R: reset to 15:00.
- Fullscreen: enlarge the timer for a classroom, meeting, or shared display.
- Keep screen on: request a temporary wake lock when the browser supports it; the visible status is authoritative.
Frequently asked questions
How do I start the 15-minute timer?
Press Start. The timer is already set to 15:00, so no setup is required. Pause freezes the remaining time, Reset returns to 15:00, and Restart begins another complete 15-minute countdown.
Can it warn me before the 15 minutes are over?
Yes. Turn on any of the optional 10-, 5-, or 1-minute checkpoints. Each selected checkpoint appears once as you cross it. Choose visual-only, gentle, or clear sound before starting, and use Test sound to check your browser volume.
Will the timer stay accurate in a background tab?
The remaining time is recalculated from the saved finish time instead of subtracting one second per browser tick. This corrects ordinary background-tab throttling. It cannot guarantee that an alarm will play while a device is asleep, a browser is suspended, or the page is closed.
What happens if I reload the page?
An active or paused countdown is restored from this browser. If the finish time passed while the page was away, the timer shows when it ended instead of silently starting over. Reset clears that saved run.
Can I keep the screen awake?
You can request Keep screen on while the timer is running. Browser and device support varies, the request may be rejected, and a wake lock is normally released when the page becomes hidden. The status beside the control reports what actually happened.
Does this timer collect my task or timing history?
No task name or history is required. The active countdown state is kept locally in this browser only so it can survive a reload. Clearing site data or pressing Reset removes the saved run.