Timer

What this countdown timer does

You type a length of time, and the timer counts down to zero. When it reaches zero, an alarm plays in your browser. The tab title shows the time left, so you can read it from another tab without switching back. The display refreshes several times a second.

The timer works from your computer's clock, not by counting ticks. That means it stays correct even if the tab is in the background or your device sleeps. A running timer also survives a page reload on the same page, because the end time is stored in the browser for that tab.

How to set a timer

Type a duration in the box and press Space to start. You can type it in several ways:

• 5 means 5 seconds.
• 5:00 means 5 minutes and 0 seconds.
• 1:30:00 means 1 hour, 30 minutes and 0 seconds.
• 90m means 90 minutes.
• 1h 30m means 1 hour and 30 minutes.
• 2d 3h means 2 days and 3 hours.

You can also type a clock time, such as 9:00, 9:00 am, 17:30 or 1730. The timer counts down to that time of day.

Presets are there for common lengths. A 5 minute timer, a 10 minute timer, a 25 minute timer and others are one click away. Each preset page has its own examples, so you can start from the length you need.

Pause, resume and the alarm

Press Space to pause. Press Space again to resume. The timer keeps the correct remaining time when you pause, because it works from the clock rather than counting ticks.

The alarm is a tone made in your browser, so no file downloads. You can pick beeps, a chime, or silent with a flashing tab title. The silent option is useful in a meeting or a library.

There is also a full-screen button that shows only the clock. On the stopwatch page, Space starts and pauses, L records a lap, and R resets. The pomodoro timer page uses 25 minutes of focus, a 5 minute short break, and a 15 minute long break after 4 rounds. All of those are adjustable.

A worked example

Suppose you want to set a timer for 10 minutes. Type 10:00 and press Space. The tab title shows the time left, so you can read it from another tab. If you pause at 4:30 and resume later, the timer still ends 10 minutes after the original start, because it uses the clock.

If you type 1.5 hours, that is 1 hour and 30 minutes, not 1 hour and 50 minutes. Decimal hours work as minutes divided by 60. So 7:30 is 7.5 hours, and 0:45 is 0.75 hours.

For a longer block, type 1h 30m. The timer counts down from 1:30:00. If you reload the page, the timer continues from the stored end time on the same page.

When to use each tool

Use this timer for a single countdown, such as steeping tea for 3 to 5 minutes, boiling an egg for about 6 or 10 minutes, or holding a plank for 30 to 60 seconds. Use the stopwatch when you want to count up and record laps. Use the pomodoro timer when you want a focus block and a break.

Other pages on the site handle date math. The date calculator finds the days between two dates. The business days calculator skips weekends and any holidays you list. The age calculator counts whole years, then months, then days. The time calculator adds and subtracts hours and minutes. The military time converter changes 1730 to 5:30 pm. The time zone converter compares zones. The unix timestamp converter turns seconds into a date.

Every day here is 24 hours. Daylight saving changes are not counted, so a day never has 23 or 25 hours on this site. That keeps the math simple and predictable.