Stopwatch & Timer
Stopwatch with lap tracking and countdown timer with alarm.
00:00.00
How It Works
The stopwatch uses performance.now() — a high-resolution monotonic clock —
combined with requestAnimationFrame for smooth display updates. Because the
elapsed time is computed as a delta from a reference timestamp (not by summing ticks),
timing stays accurate even when the tab is backgrounded or the frame rate drops.
The countdown timer alarm uses the Web Audio API to synthesize three short beeps directly in the browser — no audio files needed.