Free · No sign-up · Private

Online Stopwatch with Laps, Splits & Countdown Timer

This free online stopwatch starts in one tap. Record unlimited laps, spot your fastest and slowest splits at a glance, go fullscreen for the gym or classroom, and switch to a countdown timer with an alarm whenever you need one.

  • 1/100 s display
  • Keyboard shortcuts
  • Fullscreen mode
  • CSV export
  • Survives reloads
ReadyLap 1 · 00:00.00
00:00:00.00

SpaceStart / pauseLLapRResetFFullscreen

Laps0
Average—
Fastest—
Slowest—

Lap times

LapLap timeTotalChange

No laps yet. Press Lap (or L) while the stopwatch runs.

Why it’s better

A free online stopwatch built for real timing

Most stopwatch sites stop at start, stop and reset. This one adds the lap analysis, export and display options that coaches, teachers and testers actually need, without ads getting in the way of the clock.

Lap analysis at a glance

Every lap shows its own time, the running total and how much faster or slower it was than the lap before. Your fastest and slowest laps are highlighted automatically.

Live lap chart

A mini bar chart plots your last 24 laps, so you can see pacing drift, fatigue or a strong finish without reading a single number.

Big fullscreen display

One tap turns the clock into a huge, high-contrast readout you can read from across a room, a gym floor or a projector screen.

Countdown timer with alarm

Set any time up to 99 hours or tap a preset. A progress ring shows what is left, and a clear chime plus vibration tells you when time is up.

Export to CSV or clipboard

Copy laps straight into Google Sheets or Excel, or download a CSV file for your training log, lab notebook or timesheet.

Private and reload-safe

Everything runs in your browser and nothing is uploaded. Your time and laps are saved on your device, so an accidental refresh won’t wipe a session.

How to use

How to use the stopwatch and countdown timer

Both tools start instantly and run independently. That means you can time a workout on the stopwatch while a rest countdown ticks away on the timer.

Stopwatch in 4 steps

  1. Press StartTap Start or press the Space bar. The clock counts up in hours, minutes, seconds and hundredths.
  2. Record lapsPress Lap (or L) at the end of each lap, rep or segment. The clock keeps running while each lap is saved.
  3. Pause and resumePress Pause to freeze the time, then Resume to carry on from the same point. Paused time is never counted.
  4. Export or resetCopy or download your laps, then press Reset (or R). Reset by mistake? Tap Undo in the message that pops up.

Countdown timer in 4 steps

  1. Set the timeType hours, minutes and seconds, or tap a preset such as 1, 5 or 10 minutes.
  2. Start the countdownPress Start or Space. The ring empties as time runs down, and the browser tab shows the time left.
  3. Adjust on the flyNeed a little longer? Tap +1 min at any point, even while the timer is running.
  4. Hear the alarmAt zero you’ll hear a chime and supported phones will vibrate. Press Dismiss to stop it, or +1 min to snooze.

Keyboard shortcuts

  • SpaceStart or pause
  • LRecord a lap
  • RReset the active tool
  • FToggle fullscreen
  • CCopy lap times
  • EscExit fullscreen
Know your numbers

Lap time vs split time: what’s the difference?

The two terms get mixed up all the time, so here is the plain version. A lap time is how long one segment took on its own. A split time (also called cumulative or elapsed time) is the total on the clock at the moment you pressed Lap.

Our lap table shows both side by side, plus the change from the previous lap. In the example, the runner faded through laps 2 and 3, then found a strong kick over the final 100 m. Lap 4 is the fastest and lap 3 the slowest, which is exactly what the green and red highlights pick out for you.

Example: a 400 m run timed as four 100 m laps.
LapLap timeSplit (total)Change
100:18.4200:18.42—
200:19.1000:37.52+0.68 s
300:19.8500:57.37+0.75 s
400:18.0301:15.40−1.82 s
Use cases

Who uses an online stopwatch?

From the track to the kitchen, a reliable lap timer is one of the most useful tools you can keep open in a browser tab.

Runners, swimmers and cyclists

Time intervals, track laps and pool lengths, then paste your splits into a training log. Turn the results into pace with our pace calculator.

Students and exam practice

Time mock papers section by section, or set the countdown timer to practise under real exam conditions.

Teachers and classrooms

Put a fullscreen timer on the projector for group work, reading sprints and tidy-up time that everyone can see.

Meetings and presentations

Keep talks, stand-ups and pitches on schedule, and see exactly where the minutes went with lap markers per speaker.

Cooking and baking

Run a countdown for pasta or steeping tea while the stopwatch tracks a longer bake in the other tab.

Science and QA testing

Measure reaction times, load times or experiment steps, then export the results as CSV for analysis.

Accuracy

How accurate is an online stopwatch?

The clock itself is very precise. This stopwatch reads your device’s high-resolution monotonic timer, the same performance clock browsers use to measure page speed. It calculates elapsed time from timestamps instead of counting ticks, so it doesn’t drift if your system clock changes.

As a result, a busy tab or a slow phone can delay how often the numbers repaint, but never the time itself. Switch tabs, lock your screen or reload the page, and the stopwatch still shows the correct elapsed time when you come back.

In practice, the biggest source of error is human. Reaction time to a visual cue is roughly 0.2 to 0.25 seconds, so hand timing can be off by a tenth or two at the start and at the finish. That is fine for training, cooking and classroom work. Official races, however, use electronic timing for exactly this reason.

Tips for more accurate timing

  • Use the keyboard. Pressing Space is faster and more consistent than moving a mouse to a button.
  • Anticipate the finish. Start pressing as the runner reaches the line, not after you see them cross it.
  • Keep one person on the watch. One timer’s reaction delay stays consistent, which keeps laps comparable.
  • Turn on Keep screen on. On supported phones this stops the screen locking during long sessions.
  • Use the right tool. For fixed work and break cycles, the Pomodoro timer handles the switching for you.
Compare

Stopwatch vs timer vs Pomodoro: which should you use?

Each tool answers a different question. Pick the one that matches what you are trying to measure.

ToolHow it countsBest forOpen it
StopwatchUp from zeroMeasuring how long something takes: laps, reps, tasks, experimentsStopwatch tab
Countdown timerDown to zero, then alarmFixed limits: exams, cooking, rest periods, speechesTimer tab
Pomodoro timerRepeating work and break cyclesFocused study and deep work sessionsPomodoro timer
Time card calculatorHours from clock-in and clock-out timesTimesheets, payroll and overtimeTime card calculator
FAQ

Online stopwatch FAQs

Quick answers about laps, accuracy, the countdown timer and exporting your times.

Is this online stopwatch free to use?

Yes. It is completely free with no sign-up, no download and no limit on how long you time or how many laps you record. It works in any modern browser on desktop, tablet and phone.

How do I record lap times on the stopwatch?

Press Start, then press Lap (or the L key) each time a lap, rep or segment ends. The stopwatch keeps running while each lap is saved to the table with its lap time, total time and the change from the previous lap.

What is the difference between a lap time and a split time?

A lap time is the duration of a single segment. A split time is the total elapsed time when that lap was recorded. For example, laps of 18.42 and 19.10 seconds give splits of 18.42 and 37.52 seconds. The lap table shows both.

Does the stopwatch keep running if I switch tabs or reload the page?

Yes. It keeps timing in background tabs, and because your session is saved in your browser on this device, it picks up exactly where it left off after a reload, or even after you close and reopen the page.

How accurate is this online stopwatch?

It uses your browser's high-resolution clock and calculates time from timestamps, so the measurement stays accurate to the millisecond even if the display updates slowly. The display shows hundredths of a second. The main limit is human reaction time, which is typically around 0.2 seconds when you start and stop by hand.

Can I use the stopwatch in fullscreen on a projector or TV?

Yes. Press the Fullscreen button or the F key to show a large, high-contrast display that is easy to read across a classroom, gym or meeting room. Press Esc or F again to exit.

How do I set a countdown timer with an alarm?

Open the Timer tab, type the hours, minutes and seconds or tap a preset, then press Start. When it reaches zero, a chime plays and supported phones vibrate. You can add a minute at any time, and the stopwatch and timer can run at the same time.

Can I export my lap times to Excel or Google Sheets?

Yes. Use Copy to paste the lap table straight into a spreadsheet, or use CSV to download a file that opens in Excel, Google Sheets or Numbers.

Ready to time your next lap?

Whether you are chasing a personal best, running a classroom activity or keeping a meeting on track, this online stopwatch gives you precise laps, clear analysis and a countdown timer in one fast, private page. Bookmark it so it is one tap away next time.

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