Online Timer
Set a countdown in seconds, minutes or hours and get an alarm when it reaches zero.
How to use the Online Timer
- Set the hours, minutes and seconds, or tap a quick preset.
- Press Start — the countdown runs and can be paused any time.
- When it reaches zero, an alarm sounds and the timer flashes.
About the Online Timer
Set a countdown in hours, minutes and seconds, or tap a preset for 1, 5, 10, 15 or 30 minutes, then press Start. The display counts down to zero, with Pause and Reset there when you need them. Behind the scenes it tracks the real target time on your device's clock rather than counting ticks one by one, so if your browser slows down a background tab the timer still reaches zero at the right moment.
When time runs out the display flashes and a short alarm tone sounds. That tone is generated in the browser with the Web Audio API, so no sound file is downloaded and the alarm still works with no internet connection. The alarm is allowed to play because you pressed Start: browsers block audio that starts on its own, and your tap on Start counts as the permission they require.
A couple of honest limits: keep the tab open, because a closed tab cannot ring, and on some phones a locked screen can silence the sound, so leave the screen awake for anything important. Need to measure time going up instead of down? Use the online stopwatch. For study or work sessions with built-in breaks, the pomodoro timer runs the whole cycle for you.
Frequently asked questions
Does the timer keep accurate time if I switch tabs?
Yes. It tracks the actual target time on your device clock rather than counting seconds one by one, so even if the browser throttles a background tab to save power, it still reaches zero at the correct moment. It is best to leave the tab open, though.
Will the alarm work without an internet connection?
Yes. The alarm tone is synthesised in your browser with the Web Audio API rather than loaded from a sound file, so once the page is open it can ring with no connection. The countdown itself also runs entirely on your device.
Why did the alarm not make a sound?
Most often the tab was closed, or a phone screen was locked, which can silence audio. Keep the tab open and the screen awake. Because you pressed Start, the browser already has permission to play the tone, so an open, awake tab should ring.
Can I set a preset time quickly?
Yes. Buttons for 1, 5, 10, 15 and 30 minutes load a common countdown in a single tap. You can also type any combination of hours, minutes and seconds by hand if you need a specific length that is not on a preset.
What is the difference between this and a stopwatch?
A timer counts down from a length you set and alarms at zero; a stopwatch counts up from zero to measure how long something takes. Use this timer for cooking or focus sessions, and the stopwatch when you want to record elapsed time.