Online Stopwatch

A free online stopwatch with laps — start timing in one tap.

A free online stopwatch that counts up in hours, minutes, seconds and centiseconds with millisecond-accurate timing. Start, stop and resume in a single tap, record unlimited laps with split times, and see your fastest and slowest laps highlighted automatically. Works full-screen on any phone, tablet or computer, keeps running accurately even in a background tab, and needs no download or sign-up. Perfect for workouts, running intervals, cooking, studying, presentations and science experiments.

Online Stopwatch features

How to use Online Stopwatch

  1. Press Start

    Tap Start (or hit the Space bar) and the online stopwatch begins counting up from zero in hours, minutes, seconds and centiseconds.

  2. Record laps

    Tap Lap (or press L) whenever you complete a lap or interval — each one is logged with its own lap time and the running total.

  3. Pause and resume

    Press Pause to freeze the time, then Resume to carry on from exactly where you stopped — no time is ever lost.

  4. Compare your splits

    Your fastest and slowest laps are highlighted automatically, so you can see at a glance which interval was your best.

  5. Reset when done

    Tap Reset (or press R) to clear the stopwatch and your laps and start a fresh timing session whenever you're ready.

Frequently asked questions

Is this online stopwatch accurate?

Yes. The stopwatch measures time from your browser's high-resolution clock (performance.now) and always calculates the elapsed time from the moment you pressed Start, rather than by adding up ticks. That means it stays accurate to the millisecond and won't drift, even if you switch tabs, minimise the window or leave it running for a long time.

Does the stopwatch keep running if I switch tabs?

Yes. Browsers slow down timers in background tabs to save power, so the on-screen digits may update less often while the tab is hidden — but because the time is worked out from a real start timestamp, the moment you return the display jumps to the correct current time. No time is lost.

How do laps and split times work?

Press Lap (or the L key) each time you finish a lap. The tool records that moment, shows the lap time (how long that individual lap took) and the total elapsed time. When you have more than one lap, your fastest lap is highlighted in green and your slowest in red so you can compare your splits instantly.

Are there keyboard shortcuts?

Yes. Press the Space bar to start or pause, L to record a lap, and R to reset. The shortcuts are ignored while you're typing in a text field, so they never get in your way elsewhere on the page.

Can I use the stopwatch full-screen on my phone?

Absolutely. The stopwatch is fully responsive with large, easy-to-read digits, so it works beautifully full-screen on phones, tablets and computers. There's no app to install — just open the page and press Start.

Is the stopwatch free, and is my data private?

It's completely free with no sign-up and no limits. Everything runs locally in your browser — nothing about your timing or laps is sent to or stored on any server — so it's fast, private and ready whenever you need it.

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