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Online Countdown Timer

Free

Set a countdown timer for any duration — minutes, hours, or a specific date. Alarm sounds when it hits zero. Free, browser-based, shareable link.

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Settings guide

Setting the duration:

  • ·Enter hours, minutes, and seconds in the three fields
  • ·Or click a preset: 1 min, 5 min, 10 min, 25 min (Pomodoro), 30 min, 1 hr
  • ·Or enter a specific date and time for a long-range countdown (event countdowns)

Sound alert: The timer plays a browser-native audio alert when it reaches zero. Ensure your system audio is not muted before starting a critical timer. The alert repeats until you stop it.

Tab title display: The remaining time appears in the browser tab title (e.g., "12:35 | Countdown Timer"). You can see the time remaining in the tab strip without switching to this tab.

Shareable link: After setting the duration, the URL updates to encode the timer parameters. Copy the URL and share it — recipients open the same timer with the same duration pre-loaded.

Background behavior: Modern browsers may throttle JavaScript timers in background tabs, but this timer recomputes remaining time from the absolute end timestamp on each tick, so the display is always accurate when the tab is viewed.

Format comparison

vs a stopwatch: A countdown counts down from a set duration and alerts at zero. A stopwatch counts up from zero and you decide when to stop. Use a countdown when you have a fixed duration to track and want an automatic alert. Use a stopwatch when you want to measure how long something takes without a predetermined end time.

vs a phone timer: Phone timers are excellent and always accessible. A browser timer is preferable when you are already at a computer and want the remaining time visible in a tab without picking up your phone. Browser timers also work well in multi-monitor setups where you can have the timer visible in a corner while working in another window.

vs a physical kitchen timer: Physical timers have the advantage of never going to sleep and being visible across the room. For kitchen use, a physical timer or a voice assistant ("Hey Google, set a timer for 15 minutes") is faster. For desk work and screen-based activities, a browser countdown is always already at hand.

How it works

1

Set the duration

Enter hours, minutes, and seconds — or click a preset duration. For event countdowns, enter the target date and time.

2

Start the countdown

Press Start. The display counts down with the remaining time updating every second. The tab title shows the remaining time.

3

Alert at zero

When the timer reaches zero, an audio alert fires. The timer resets to the original duration so you can restart immediately for the next interval.

About this format

A countdown timer counts down from a set duration to zero and alerts you when time is up. The fundamental use is universal: you need to do something for a specific amount of time without watching the clock. Set the timer, do the thing, the alert tells you when to stop.

The use cases span everything. Cooking: 12 minutes for pasta. Presentations: 20 minutes per speaker, with an alert. Exam practice: 90 minutes timed. Workout rest: 60 seconds between sets. Classroom: 15 minutes for a group activity. Meeting management: alert the speaker at 25 minutes. Brewing: 4 minutes steep time.

The browser-based countdown timer has a practical advantage over a phone timer in many contexts: it is visible on your screen while you work. A phone timer requires you to pick up the phone to check remaining time. A browser timer displays in the tab title, so you can see remaining time in the tab strip without switching to it.

This timer generates a shareable URL encoding your duration. Send the URL to a meeting participant and they start their own synchronized countdown. Useful for distributed teams running the same timed activity simultaneously.

Frequently asked questions

Can I set a countdown timer for more than 24 hours?+
Yes. Enter the hours field with any value — the timer is not limited to 24 hours. For multi-day countdowns (event launch countdowns, deadline countdowns), switch to date-mode and enter the target date and time directly. The display shows days, hours, minutes, and seconds remaining for durations longer than 24 hours.
Will the alarm sound if the browser tab is in the background?+
Most browsers allow audio to play in background tabs if the tab has previously had user interaction (which it has, since you started the timer). The alert should sound even when the tab is backgrounded. However, mobile browsers running in the background may suppress audio depending on battery saver settings and browser restrictions. For critical timing on mobile, keep the browser tab in the foreground.
Can I have multiple timers running simultaneously?+
Yes — open the countdown timer in multiple browser tabs. Each tab runs independently. You can set different durations on each tab and run them simultaneously. This is useful for cooking multiple items with different cooking times, or managing multiple parallel tasks with different deadlines.
Does the countdown timer work offline?+
Once the page is loaded, the timer works without an internet connection. The countdown logic runs entirely in JavaScript in your browser with no server dependency. If you lose connectivity after loading the page, the timer continues correctly. Refreshing the page while offline may not load the app, so avoid refreshing during an active timer if your connection is unstable.
How do I use the countdown timer for a meeting where everyone needs to see it?+
Open the timer and set your duration. The URL automatically encodes the timer parameters — copy the URL and share it with participants. Each person opens the URL and sees the same timer duration. They start it independently — there is no synchronized start built in. For a shared screen scenario, simply project or share your screen showing the running timer. The tab title display is also useful for participants who can see your window in a video call.

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