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TimerHub

45 Second Timer

Free online 45 second countdown timer with alarm

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Quick timers

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Use this timer in your workspace
45s timer45 sec timertimer 45 secondsset a timer for 45 seconds

More ways to run this timer

Run it with rain, waves or a focus pad Same countdown, with an ambient bed that fades out at zero. No video, no ads.Need a visual countdown instead? Sand, candle, rocket, traffic light and seven more — built for projectors and classrooms.Build repeating work and rest rounds in the Interval Timer

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Take this timer with you

Keep it beside your work in Notion, or embed it on your website. No account or ads. Includes anonymous usage analytics.

In Notion, type /embed and paste this link. Resize the block to fit.

Customise colour, duration and size →Use in Google Docs or Canva →

About the 45 Second Timer

A 45 second countdown with a display large enough to read across a room, keyboard shortcuts, and an alarm at zero. Built for intervals, rest periods and game rounds — no ads, no signup.

TimerHub calculates remaining time from an absolute finish timestamp, so missed browser callbacks do not create drift. Read the timing accuracy methodology and reproducible tests.

Common Uses

  • HIIT work interval
  • Plank hold
  • Rest between sets
  • Speed challenge
  • Game round countdown

How to Use the 45 Second Timer

  • Press Start — or the Space bar — to run the 45 second countdown. Space also pauses and resumes it; R resets it
  • Adjust by 10 seconds with the +/- buttons while it runs, toggle Repeat to loop it, and check the finish time shown under the display
  • Use the Fullscreen control below the timer for a room-sized countdown (Esc to exit)
  • Choose or mute the alarm in the header's sound settings, and pick a background sound — rain, ocean, fireplace or brown noise — that fades out at zero
  • Enable notifications to be alerted when your 45 second timer finishes in a background tab, and add ?autostart=1 to the link to start the countdown on load

Frequently Asked Questions

How long is 45 seconds?

45 seconds is less than a minute. Our free 45-second timer gives you a precise countdown with an alarm at the end.

What can I use a 45 second timer for?

A 45 second timer is perfect for hiit work interval, plank hold, rest between sets. Hit Start and the countdown begins instantly.

Does the timer work in the background?

Yes, our timer continues running even if you switch to another tab or minimize your browser. Enable notifications to get alerted when it finishes.

Does the alarm sound when the timer finishes?

Yes, an alarm plays automatically the instant the 45 second countdown hits zero, with an optional vibration on mobile. Enable notifications for an extra alert in background tabs.

Can I make the timer fullscreen?

Yes, use the Fullscreen control below the timer to show a large full-screen countdown that is easy to see across a room or gym. Press Esc to exit fullscreen.

Can I use this 45 second timer on mobile?

Yes, our 45 second timer works on all devices including phones and tablets. No app download needed — just open this page in your mobile browser.