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Online Stopwatch & Timer

Free online stopwatch with lap tracking and countdown timer with presets. Precise to the millisecond.

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About This Tool

Stopwatch — precision timing with lap tracking, perfect for workouts, cooking, or experiments
Countdown Timer — set any duration with quick presets, visual progress bar, and alarm notification
Runs entirely in your browser — no apps to install
Millisecond precision using requestAnimationFrame

About Online Stopwatch & Timer

Free online stopwatch and countdown timer that runs in your browser with millisecond precision. The stopwatch mode features start, pause, resume, reset, and lap tracking — perfect for timing workouts, experiments, cooking, or any activity. The countdown timer mode lets you set any duration with quick presets (1, 3, 5, 10, 15, 30 minutes, 1 hour), shows a visual progress bar, and alerts you when time is up. Uses requestAnimationFrame for smooth, accurate timing. No apps to install, no signup required — just open and start timing.

Frequently Asked Questions

How accurate is the stopwatch?▾

The stopwatch uses requestAnimationFrame, which provides timing precision of approximately 1 millisecond on modern browsers. It displays time with centisecond (1/100th of a second) resolution. For everyday timing needs, this is more than accurate enough. Note that browser tab switching may slightly affect precision.

Will the timer work if I switch tabs?▾

Yes. The timer uses absolute timestamps (Date.now()) rather than counting intervals, so switching tabs does not cause drift. The displayed time updates when you return to the tab. However, the visual progress bar animation may pause in background tabs.

Can I use the stopwatch and timer at the same time?▾

The tool shows one mode at a time (stopwatch or timer), but switching between modes does not reset either one. You can start a stopwatch, switch to the timer tab, set a countdown, then switch back — both maintain their state independently.

Does the timer make a sound when it finishes?▾

The timer displays a visual alert (pulsing text and color change) when the countdown reaches zero. Browser audio notifications depend on your browser's autoplay policy. For the most reliable experience, keep the tab open and visible.