Don's Tools · Calculators · Countdown & Stopwatch

Countdown & stopwatch

A countdown timer and a stopwatch in one, right in your browser. Nothing is uploaded.

Mode
Hours
Minutes
Seconds
05:00
Good to know: The countdown beeps when it finishes, so keep your sound on.
Countdown and Stopwatch combines a countdown timer and a stopwatch on a single page, running entirely in your browser with nothing uploaded. The countdown beeps and flashes when it finishes, the stopwatch records laps and splits to a hundredth of a second, and both stay accurate using the real elapsed time.

Files are processed in your browser and never uploaded.

How to use Countdown & stopwatch

  1. Enter your figures

    Fill in Hours, Minutes and Seconds. Values you change are used straight away, with no submit button.

  2. Read the results

    The totals and the breakdown below them update as soon as a value changes.

  3. Start over any time

    Nothing is saved on a server, so reloading the page clears everything.

What this tool does

Countdown timer with alarm

Set hours, minutes and seconds, press start, and an alarm sounds when it reaches zero.

Stopwatch with laps and splits

The stopwatch records laps as you go, so a set of intervals is timed and listed rather than remembered.

Switch modes in one tap

Mode switches between Countdown and Stopwatch without losing what the other one was doing.

Accurate even in the background

The time is worked out from the clock rather than counted frame by frame, so it stays accurate when the tab is in the background.

Works offline, no sign-up

Once loaded the page keeps running with no connection, with no account and nothing uploaded.

Frequently asked questions

Are they accurate?

Yes. Both track the real elapsed or remaining time rather than counting frames, so they stay accurate even if the tab is in the background, though the page must stay open to alert you.

Is anything uploaded?

No. Everything runs in your browser with nothing uploaded, and it works offline.

Will the countdown make a sound?

Yes, it beeps repeatedly and the screen flashes when it finishes. Keep your device sound on; on mobile you may need to tap the page once so the browser allows audio.

Can I record laps on the stopwatch?

Yes. Switch to Stopwatch mode and press Lap while running to record each split and the running total.

What is the difference from the separate timer tools?

This combines a countdown and a stopwatch on one page so you can switch between them quickly. The separate Countdown Timer and Stopwatch tools work the same way if you prefer them individually.

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