This page runs a 45 second countdown and sounds an alarm when it ends. It is for anyone who needs to time a short burst of work, a hold, or a quick task without watching a clock.
What fits inside 45 seconds
Forty-five seconds is long enough for a hard effort and short enough that you will not lose focus. It is the top end of a HIIT work interval, which often runs 20 to 45 seconds. It is also a common hold time for a plank or a wall sit, and a natural rest between sets when you want to keep moving. In a classroom, 45 seconds works as a quick quiz section or a think-pair-share before you call on anyone. A short reading sprint can fit here too if you only need one paragraph.
The countdown reads from your computer's clock, not by counting ticks. That means it stays accurate when the tab is in the background or your device sleeps. The display refreshes several times a second, so the last few seconds look smooth. The tab title shows the remaining time, so you can read it from another tab. A running timer survives a page reload on the same page, because the end time is stored in the browser for that tab.
Frequently asked questions
How do I set a timer for 45 seconds?
Open the timer and type 45 into the duration field, or press the 45 second preset if it is showing. Press Space or the start control. The countdown begins from your computer's clock, so it stays accurate even if you switch tabs.
Does the 45 second timer keep running if I close the tab?
No. A running timer survives a page reload on the same page, because the end time is stored in the browser for that tab. If you close the tab, the timer is gone. Keep the tab open or use the tab title to watch the time.
Can I change the 45 second timer to a different length?
Yes. Type any duration you need, such as 30, 1:30, or 90m. You can also enter a clock time like 17:30. The alarm choices are beeps, a chime, or silent with a flashing tab title.