Stopwatch & countdown timer

Stopwatch and timer in the browser

The stopwatch measures down to tenths of a second using the browser's high-precision clock and lets you record laps, useful for interval training, exams or presentations. The countdown emits a triple beep when it reaches zero and changes the tab title, so you notice even if you are in another window.

Nothing needs to be installed: it works on mobile and desktop. Note that if you close the tab the time stops; for long timers with the screen off, your phone's clock app is still the best option.