Online Stopwatch & Countdown Timer

High-precision millisecond stopwatch with lap recording and customizable countdown alarm with Web Audio beeper alerts.

Local Browser Execution: Runs completely client-side in browser memory with zero network dependencies.

t_elapsed = Date.now() - t_start

Understanding Your Results

Provides large high-contrast digits with milliseconds display, lap history records, and audio buzzer alarm upon completion.

Use quick preset buttons (5 min, 15 min, 25 min Pomodoro) to launch countdowns with 1 click.

Technical Scope & Calculation Limitations

Timers run while the browser tab is open. If your computer goes to sleep, the timer will pause until wake.

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