Online Timer
A free online timer: set a countdown, start it, and hear an alarm when time is up.
- Free
- No sign-up
- Alarm sound
- Full screen
Online timer
Timer
Reset the timer? It still has time left.
Quick timers
Sound and display
70%
Keyboard: Space to start or pause, R to reset, F for full screen, Esc to stop the alarm. Turn shortcuts off under Sound and display.
How to use the online timer
- Tap a quick timer to start it right away, or type hours, minutes, and seconds and press Start.
- Add a label if you're running it for a class or a recipe. It shows above the digits and in the browser tab.
- Pick an alarm sound under Sound and display, and press Test sound once to check your volume.
- When time is up, the screen turns red and the alarm plays. Press Stop or the Esc key. Reset brings back the same time for another round.
Want it to ring at a time of day, like 6:30 AM, instead of after a set length? Use the alarm that rings at a clock time. For work and rest rounds, the Tabata and HIIT timer switches between them for you.
Will it work in the background or with the screen off?
In a background tab, yes. Browsers slow down page scripts in tabs you aren't looking at, so this timer doesn't count ticks. It saves the moment it should end and compares the clock to it, and it schedules the alarm on the browser's audio clock when you press Start.
With the screen off, it depends on your device. Phones often pause web pages and their sound when they lock. Keep screen awake asks the browser to keep the display on while the timer runs, in browsers that support it. For anything important, keep the page open and the screen on.
More timers and time tools
- StopwatchCount up with laps, notes, and a CSV download.
- Timer calculatorFind what time a timer will end, from now or any start time.
- Hours from nowWhat time it will be in 1 to 24 hours.
- Classroom timerA big shrinking disk you can show without numbers, renamable activity buttons, a time warning, and a soft chime that plays once.
- Interval timerTabata, HIIT and EMOM rounds with work and rest beeps.
- Focus timerFocus sessions and breaks that follow each other, with a list of today's sessions.
- Online alarm clockRing at a clock time, like 6:30 AM, instead of after a set number of minutes.
- 1 minute timerOne tap for a minute, or repeat rounds with rests for drills.
- Speech timerWork out how long a speech runs, then rehearse it with green, yellow and red signals.
- 5 minute timerA break timer with gentle bells and a sign showing when you'll be back.
- 10 minute timerFocus blocks with warnings before the end and a log of blocks done today.
- How long until a timeCount to a clock time like 5:00 PM, then send the time left here.
Online timer questions
Will the timer keep running if I switch tabs?
Yes. The timer stores the exact moment it should end and checks the clock against it, so it doesn't fall behind when a browser slows down background tabs. The alarm is scheduled on the browser's audio clock when you press Start, so it can sound on time even while you're in another tab.
Why didn't I hear the alarm?
Browsers don't allow a page to play sound until you've clicked or tapped it, so sound only works once you press Start or Test sound. Also check that the sound isn't set to Silent, that your device volume is up, and on a phone that the silent switch is off. Phones can stop sound when the screen locks, so turn on Keep screen awake for anything important.
Can I show it full screen on a TV, display or projector?
Yes. Press Full screen or the F key. The digits and ring scale up to fill the screen and everything else is hidden. If your browser can't go full screen, the timer expands to fill the page instead.
Does it keep my timer if I refresh the page?
Yes. A running or paused timer is saved in your own browser, so a refresh picks up where it left off. Sound needs one tap after a refresh before it can play again, and the page will ask for it. Nothing is sent to a server.
Can I add time while it runs?
Yes. Use +1 min or +30 s, or −30 s to take time off. The end time updates as you go.
How do I set a timer for a specific clock time?
Use How long until a time: enter the clock time, like 3:15 PM, and press Start a timer for this. It opens this timer with the time left filled in. To ring at a time of day without a countdown, use the online alarm clock.
Sources
- Chromium project, "Autoplay policy in Chrome" (sound needs a click or tap first), chromium.org
- Chrome for Developers, "Heavy throttling of chained JS timers beginning in Chrome 88" (background tabs slow down timers), developer.chrome.com
- web.dev, "The Screen Wake Lock API is now supported in all browsers" (Keep screen awake), web.dev
- Apple Developer Forums, full screen support on iPhone Safari, developer.apple.com
The online timer on TimerCalculator.com was built by Cedrick Reese. It counts down against the exact end time instead of counting ticks, which keeps it accurate when a tab is in the background. It was tested in an automated browser with a simulated clock: a 1 minute quick timer was run to zero to confirm the Time's up screen and the Stop button, the clock was jumped ahead the way a sleeping background tab would see it and the digits were checked against the end time, the alarm was confirmed to be booked for the exact second the countdown ends, and the page was reloaded mid-run to confirm the countdown carried on. Your settings and any running timer are saved only in your own browser.