Stopwatch

A precise online stopwatch with lap times

Time a run, a lab step, a speech, a game or any task that needs an exact duration. The stopwatch shows minutes, seconds and hundredths of a second, and it records laps so you can compare splits.

How to use it

1. Press Start to begin timing.
2. Press Lap at each split. Each lap shows both the lap time and the total time so far.
3. Press Stop to pause, then Start to resume, or Reset to clear the display and laps.
4. Review the list of laps. The fastest lap is highlighted in one color and the slowest in another, which makes pacing easy to judge.

Lap time versus split time

A lap time measures how long a single segment took, while the total (or split) time is the running clock since you began. If your first lap took 1:05 and your second took 1:10, the second lap time is 1:10 and the total at that point is 2:15. Watching lap times helps you see whether you are speeding up, holding steady or fading.

Ideas for using a stopwatch

• Running and swimming. Record each lap of a track or pool and compare them.
• Study and work. Track how long tasks take so you can plan better.
• Cooking and lab work. Time steps that need to be repeated exactly.
• Public speaking. Practice a talk and mark the time at each section.
• Games and challenges. Keep score fairly with an accurate clock.

Accuracy notes

The stopwatch reads your device’s high-resolution clock rather than counting screen updates, so the total stays accurate even when the display refreshes slowly. Human reaction time, usually around a fifth of a second, is the biggest source of error when pressing buttons. For official competition timing, use certified equipment.

Frequently asked questions

Does it keep running if I switch tabs?

Yes. Because time is calculated from the clock, the total is correct when you return, but keep the tab open.

How many laps can I record?

As many as you need. The list scrolls.

Are my times saved?

No. Laps disappear when you reset or close the page.