Online Stopwatch: Precise Timing with Lap Recording
A stopwatch is an essential timing tool used in sports, cooking, scientific experiments, productivity techniques, and countless everyday tasks. Unlike a countdown timer that counts down to zero, a stopwatch counts up from zero, measuring the exact duration of an activity or event. Our online stopwatch provides precision timing directly in your browser with no installation required.
The stopwatch displays time in HH:MM:SS.ms format, showing hours, minutes, seconds, and centiseconds (hundredths of a second). It uses the browser's high-resolution performance timer (performance.now()) combined with requestAnimationFrame for smooth, accurate updates. This approach avoids the timing drift that can occur with setInterval and provides the most precise timing available in a web browser.
The lap feature allows you to record split times while the stopwatch continues running. Each lap records both the individual lap duration and the cumulative total time. Laps are displayed in reverse chronological order (newest first) for easy reading. This is particularly useful for runners tracking mile splits, swimmers timing laps, or anyone measuring repeated intervals.
Controls are intuitive: Start begins timing, Stop pauses without resetting, allowing you to resume later. Reset clears everything back to zero. The Lap button records a split time without interrupting the stopwatch. The large, clear display makes it easy to read the time even from a distance, making it suitable for use in classrooms, gyms, and presentation settings. All timing happens client-side with zero network latency.