About the Online Timer
This online timer counts down from any length of time you choose and sounds an alarm when it reaches zero. Tap a preset — 1, 3, 5, 10, 15, 20, 30 or 60 minutes — and it starts straight away, or type exact hours, minutes and seconds and press Start. You can pause, resume, add a minute or reset at any time, and the page title shows the time left so you can see it from another tab.
Use it as a kitchen or cooking timer, a study or focus timer, a workout and rest timer, a classroom or meeting timer, a presentation time-keeper or a reminder to take a break. The timer is based on the system clock, so it stays accurate even when the tab is in the background.
Below the live timer, the planner shows the total length in minutes and seconds and — if you enter a start time — the exact clock time the timer will finish. Keep your device’s volume on to hear the alarm; browsers only play sound after you have interacted with the page.
With the default inputs, the timer length is 5m. Change any value above to recalculate instantly.
How to use the online timer
- 1Tap a preset such as 5 or 10 minutes to start at once, or type hours, minutes and seconds.
- 2Press Start (or Space while the timer panel is focused) to begin the countdown.
- 3Pause, add a minute or reset whenever you need to.
- 4Listen for the alarm and press Stop to silence it.
Formula and method
The timer converts your hours, minutes and seconds into one total in seconds and records the exact moment you press Start. The display shows the total minus the time elapsed since then, so it cannot drift even if the browser slows down background tabs.
When the remaining time reaches zero an alarm tone plays (generated with the Web Audio API) and the page title changes to “Time’s up!”. Pausing stores the time left; resuming starts a new countdown from that amount. The planner adds the total to your start time to show the finish time on a 12-hour clock.
- Total
- Timer length in seconds
- Remaining
- Total − (now − start moment)
Worked examples
5-minute timer started at 9:00 AM
Five minutes is 300 seconds, so a timer started at 9:00 AM goes off at 9:05 AM.
1 h 20 min 30 s roast timer at 5:50 PM
1 hour 20 minutes 30 seconds is 3,600 + 1,200 + 30 = 4,830 seconds. Starting at 5:50 PM, it finishes at 7:10:30 PM.
90-minute study session starting at 11:15 PM
Ninety minutes is 1 hour 30 minutes; from 11:15 PM that runs past midnight to 12:45 AM the next day.
Frequently asked questions
How do I set a 10-minute timer?+
Tap the 10 min preset and the countdown starts immediately, or enter 10 in the minutes box and press Start. An alarm plays when it reaches zero, and +1 min extends it if you need longer.
Will the timer work if I switch tabs?+
Yes. The timer measures time from the system clock, so it stays accurate in a background tab and the tab title shows the time left. Keep the tab open — closing it stops the timer.
Why didn’t I hear the alarm?+
Check that your device is not muted and the volume is up. Browsers block sound until you interact with the page, so press Start yourself rather than relying on an automatic start.
Can I pause and resume the timer?+
Yes. Press Pause to freeze the countdown and Resume to continue from the same time left. Use +1 min to extend a running timer and Reset to start over.
What is the difference between a timer and a stopwatch?+
A timer counts down from a set length and alerts you at zero; a stopwatch counts up from zero to measure how long something takes. Use the online stopwatch when you want to record lap times.