How does the stopwatch 'Lap' feature work?

When you click the 'Lap' button, the stopwatch records the current elapsed time without stopping the main timer. This is useful for timing segments of an activity, like laps in a race or intervals in a workout.

Will the timer alarm sound if my browser is in the background?

Yes, in most modern browsers, the alarm sound will play even if the tab is not active. However, if you close the browser tab or window, the timer will stop.

Is my data (laps, timer settings) saved?

No, this is a simple, session-based tool. All your lap times and timer settings will be cleared when you close or refresh the page.

Online Stopwatch & Timer | CalculatorHari.com

How Does This Work?

This tool combines two essential time-keeping functions into one simple interface.

Stopwatch: When you click 'Start', the stopwatch begins counting up from zero, updating every 10 milliseconds for accuracy. The 'Lap' button captures the current elapsed time without interrupting the main count, perfect for timing segments of an activity.
Timer (Countdown): You set a specific duration (hours, minutes, seconds). When you click 'Start', the timer begins counting down. It uses a precise interval to update the display every second. When the countdown reaches zero, it plays an audible alert to notify you that the time is up.

The Surprising History of the Chronograph

The ability to accurately measure short intervals of time was a major challenge for centuries. The modern stopwatch, or chronograph, has its roots in the world of horse racing. In 1821, a French watchmaker named Nicolas Mathieu Rieussec was commissioned by King Louis XVIII to time horse races.

Rieussec's invention was ingenious: it was a clock mechanism with a pen nib attached to the second hand. When a horse crossed the finish line, a button was pressed, causing the pen to drop and make an ink mark on the rotating clock dial. An observer could then see the exact time of the finish. He called it a "chronograph," from the Greek words *chronos* (time) and *graphein* (to write). This "time-writing" device was the direct ancestor of every stopwatch we use today, from analog race timers to the digital apps on our phones.

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Frequently Asked Questions (FAQ)

Does the stopwatch run in the background?

In most modern browsers, the stopwatch will continue to run if the tab is in the background. However, if you close the browser tab or window, the timer will be lost. This tool is designed for active, in-the-moment timing.

Can I customize the timer alarm sound?

Currently, the timer uses a standard, built-in alert sound for simplicity and universal compatibility across all browsers. Custom alarm sounds are not supported at this time.

What is the precision of the stopwatch?

The stopwatch display updates every 10 milliseconds, showing time down to the hundredth of a second. This is accurate enough for most common applications, such as workouts, cooking, and study sessions.