タイマー・ストップウォッチ

This tool combines a countdown timer and a stopwatch in one. The timer counts down from a time you set and sounds an alarm when it finishes; the stopwatch counts up and records laps.

It covers the everyday timing jobs: cooking and baking, workout intervals and rest periods, a Pomodoro focus session, timing a presentation or a speech, or a board-game turn.

Everything runs in your browser and nothing is saved or uploaded, so just make sure the tab is not muted if you want to hear the alarm.

For the timer, set hours, minutes and seconds and start the countdown. When it reaches zero a short beep plays and the display highlights, so you notice even if you have looked away.

The stopwatch counts up from zero, and the lap button records the current time without stopping, so you can capture split times, one per lap, listed below the clock.

Times are tracked from precise timestamps rather than a simple counter, so they stay accurate even if the tab is inactive for a while. Background tabs may update the display less often, but the elapsed time stays correct when you return.