Stopwatch & Timer
A 0.01s stopwatch and a minute-based countdown timer on one screen. Use it for workouts, cooking, exams, and presentations.
Lap times
How to Use
Switch tabs between Stopwatch (count up) and Timer (count down).
Start → time counts up at 0.01s precision. Tap "Lap" to record a split; "Stop" then "Reset" to clear.
Type minutes/seconds or pick a preset (1, 5, 10, 30 min) and Start. An alert plays at zero. Toggle 🔔/🔕 to mute.
FAQ
How accurate is the stopwatch?
Uses requestAnimationFrame + performance.now() at 0.01s (10 ms) precision. Drift, pauses, or background-tab throttling don't affect it because elapsed time is computed from a stored start timestamp on every render.
What is a lap?
While running, "Lap" records the cumulative time and the delta from the previous lap. Useful for interval workouts and round timing. Laps are cleared on Stop / Reset.
I can't hear the timer alert.
Browsers only allow audio after a user gesture — pressing Start enables it. On mobile, even silent (vibrate) mode blocks audio; turn it off. Use the bell icon to mute.
Does it stay accurate in background tabs?
Yes. Even if setInterval is throttled, the timer reads the real elapsed time from the stored start and re-syncs immediately when the tab becomes active.
Is anything sent to a server?
No. All timing happens in your browser; nothing leaves the page.
