Online Stopwatch

A stopwatch that lives in your browser is always within reach: for timing workouts and rest intervals, cooking, presentations, science experiments, speed-cubing or timing how long a task really takes. Our free online stopwatch shows minutes, seconds and hundredths with a large, glare-friendly display. Record laps as you go and it lists both the lap time and the total elapsed time for each split, which you can copy for your training log or lab notes. It keeps running accurately even if you switch tabs.

Quick Answer: Press Start and the stopwatch runs with hundredths of a second. Use Lap to record split times, Stop to pause, and Reset to clear. Timing is based on real clock time, so it stays accurate in the background.

Free Online Tool

Precision timing with laps, based on the real clock.

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Table of Contents

How to Use the Online Stopwatch

Press Start when you are ready; the display begins counting immediately.
Press Lap at each checkpoint to record a split without stopping the clock.
Press Stop to pause the time; press Start again to resume where you left off.
Review the lap table: each row shows the lap number, that lap’s duration and the total time at the split.
Copy the results if you need them in a log, then press Reset to prepare for the next timing.

Key Features

Hundredths-of-a-second display for precision timing.
Unlimited lap recording with both lap duration and cumulative split shown.
Accurate by design: elapsed time is calculated from the system clock, not by counting screen updates, so background tabs do not drift.
Large high-contrast display that is easy to read at a distance or in motion.
Copyable lap table for training logs, experiments and race results.

Best Practices and Tips

For self-timing, start the watch before the ‘go’ moment of your activity rather than trying to press and move simultaneously.
Record a lap at every repetition or checkpoint as you go; reconstructing splits afterwards from memory is unreliable.
In experiments, run a trial timing first to check your process; the first use of any timer in a new setup is usually the sloppiest.
If you need a countdown that alerts you at zero instead, use the Countdown Timer tool; stopwatches count up and stay silent.

Common Mistakes to Avoid

Leaving the stopwatch running in a forgotten tab and returning to a meaningless five-hour reading; reset between sessions.
Trusting hundredth precision for human reaction tasks: your own button press adds roughly two-tenths of a second of reaction error.
Comparing lap times recorded under different conditions as if they were identical tests; note the conditions beside the results.

Frequently Asked Questions

How accurate is this online stopwatch?

The elapsed time is computed from your device’s clock each time the display refreshes, so it is accurate to within a few hundredths of a second in normal use. The display itself refreshes many times per second; human reaction time when pressing buttons is the main source of error.

Does it keep working if I switch tabs or minimise the browser?

Yes. Because timing is based on the real clock rather than a counter, switching tabs, or even the screen sleeping briefly, does not lose time. When you return, the display shows the true elapsed time.

What is the difference between lap time and split time?

A split is the total elapsed time when you pressed Lap. The lap time is how long that individual segment took, calculated as the difference between consecutive splits. The table shows both, like professional timing systems.

Can I use it for official sports timing?

For training and informal events it is excellent. Official competition results require certified equipment and officials, so treat this as a training and convenience tool.

Is there a maximum time it can measure?

The counter runs for days if left open, rolling past 99 minutes into hours. For multi-day timing, a date-based tool or a dedicated logging app is more practical.