A clean, precise stopwatch with lap times and a countdown timer. Millisecond accuracy using the Performance API. Works in any browser, no installation needed.
This stopwatch uses the Performance API (performance.now()) which provides sub-millisecond precision, more accurate than Date.now(). It is accurate to within a few milliseconds for typical use.
Yes — switch to Countdown mode, set hours, minutes, and seconds, then press Start. A progress bar shows time remaining. An alert sounds when time runs out.
A lap time records the elapsed time at a specific moment (split) and shows the time since the last lap. Use it for running, swimming, or any activity with repeated segments.
Modern browsers throttle JavaScript in background tabs to save battery. For precise timing, keep the stopwatch tab active and visible. For countdown timers, the end time is stored so accuracy is maintained.
The Pomodoro Technique uses 25-minute focused work sessions followed by 5-minute breaks. Use the 25-minute countdown preset in Countdown mode. After 4 Pomodoros, take a longer 15-30 minute break.
This stopwatch handles one timer at a time. For multiple simultaneous timers, open multiple browser tabs — each tab runs its own independent timer.
Switch to Countdown mode, enter your cooking time, and press Start. The progress bar gives a visual indicator of time remaining. The alert notifies you when time is up.