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Online Stopwatch & Timer

Online stopwatch with millisecond precision, lap/split recording, and fastest/slowest lap stats. Ideal for training, presentations, and any timing scenario.

How to Use

  1. Step 1: Click Start to begin the timer.
  2. Step 2: Click Lap to record split times.
  3. Step 3: Click Stop to pause and Reset to clear.

Frequently Asked Questions

What is a chronometer?

A chronometer is a precise timekeeping device used to measure elapsed time commonly used for sports benchmarks and timing events.

Does closing the tab stop the timer?

Yes, closing or refreshing the tab will reset the timer since it runs in the browser JavaScript context.

What is the difference between a stopwatch and a countdown timer?

A stopwatch counts up from zero recording elapsed time. A countdown timer counts down to zero. This tool is a stopwatch with lap recording, useful for sports training, presentations, and meeting timing.

How does a timer achieve precise timing in JavaScript?

JavaScript's performance.now() provides sub-millisecond precision and is unaffected by system clock adjustments, making it more accurate than Date.now(). Timers typically use setInterval or requestAnimationFrame to update the display. For long-running timers, requestAnimationFrame is more energy-efficient, syncs with the screen refresh rate, and avoids excessive computation in background tabs.