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DayUtils

Online Stopwatch – Free Stopwatch with Lap Times

A simple, accurate stopwatch that runs in your browser. Start, stop and reset with one tap, record lap times, and see your fastest and slowest laps highlighted. Use the space bar to start and stop and the L key for laps.

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How to use the stopwatch

  1. Press Start (or the space bar) to begin.
  2. Press Lap (or L) to record a split while it keeps running.
  3. Press Stop (or the space bar) to pause. Press Resume to continue.
  4. Press Reset to clear the time and laps.

The time is shown as minutes, seconds and hundredths — and hours once you pass 60 minutes.

Lap times and split times

Each lap row shows two numbers:

  • Lap time — how long that lap took on its own.
  • Total time — the stopwatch reading when you pressed Lap, often called the split.
Lap time = This split − Previous split

With three or more laps, the fastest is shown in green and the slowest in red, so you can see at a glance where you sped up or slowed down.

Example: a 1,600 m run on a 400 m track

LapLap timeTotal
11:42.301:42.30
21:45.103:27.40
31:47.855:15.25
41:39.606:54.85

The last lap was the fastest — a strong finish — and lap 3 the slowest.

Ways to use a stopwatch

  • Running, swimming and cycling intervals and laps.
  • Workouts: plank holds, rest periods and circuits.
  • Cooking: timing steps when you don’t know the end time in advance.
  • Presentations and speeches: rehearse to fit a time slot.
  • Science experiments in class.
  • Games and quizzes: timing rounds or puzzles.
  • Productivity: measure how long tasks really take.

Getting accurate times

  • Watch the start and finish, not the screen, and press as the event happens.
  • Use the keyboard on a computer; a key press is quicker than a mouse click.
  • Keep the same person on the button for consistent reaction time.
  • For official races, electronic timing is used because hand timing varies by a few tenths of a second.

Interval training with laps

For intervals, press Lap at the end of each hard effort and again at the end of each recovery. The lap list then shows work and rest times alternately, which makes it easy to check you are keeping efforts consistent. Coaches often look for the fastest and slowest laps to be within a few seconds of each other; a big gap usually means the first repetitions were too fast.

For counting down instead of up, use the countdown timer. Turn running times into pace with the pace calculator, and add up work hours with the hours calculator. The stopwatch runs entirely in your browser.

Frequently asked questions

How accurate is the online stopwatch?

It reads your device’s high-resolution clock and shows hundredths of a second. The display is updated with every screen refresh, so it stays accurate even if the page is busy. The real limit is human reaction time — usually 0.1 to 0.25 seconds.

How do I record laps?

While the stopwatch is running, press Lap or the L key. Each lap shows its own time and the running total; the fastest lap is green and the slowest red once you have two or more.

What keyboard shortcuts can I use?

Space starts and stops the stopwatch, and L records a lap. Shortcuts work when the page has focus and you aren’t typing in a box.

Does it keep running if I switch tabs?

Yes. The stopwatch is based on the clock time when you started, so the elapsed time is correct when you come back, even if the display paused in the background.

Can I save my laps?

Press Copy above the lap list to copy all lap times as text, then paste them into a note, spreadsheet or message.

What is the difference between a stopwatch and a timer?

A stopwatch counts up from zero to measure how long something takes. A timer counts down from a set time. For a timer, use the countdown timer.

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