Stopwatch & Timer

How this calculator works

An online stopwatch is the simplest timing tool there is: press start and it counts up with centisecond precision. The lap button records both the split (this lap) and the running total, which makes it useful far beyond running tracks: speakers timing rehearsal sections, teachers running classroom activities, developers benchmarking tasks, cooks juggling dishes. The fastest and slowest laps are highlighted automatically, so a glance tells you where the pace changed.

The countdown tab flips the job around: set hours, minutes and seconds, or hit one of the quick presets from 1 minute to 1 hour, and watch the progress bar drain toward zero. When time runs out the page plays an alarm and flashes a green "time is up" state. It is the tool for HIIT and Tabata workout rounds, exam practice under real time pressure, presentation rehearsals, and every kitchen task that punishes guessing.

The third tab is a Pomodoro timer for the focus technique of the same name: 25 minutes of deep work, a 5-minute break, and a longer 15-minute break after every four sessions. The cycle dots track your progress and the timer advances phases automatically with a chime, so you never have to watch the clock. Every length is adjustable if 25/5 is not your rhythm. One honest caveat: browsers slow down background tabs to save battery, so keep this page visible for exact timing. Like every tool here, everything runs locally in your browser with no account and nothing uploaded.