Stopwatch Online

The stopwatch stores the moment you started and the milliseconds you had already accumulated, then derives the reading from the system clock on every frame. That distinction matters, because browsers throttle timers in background tabs. A stopwatch that counts its own ticks falls behind as soon as you look away; one that reads the clock does not. Switch tabs, lock the phone, come back an hour later, and the elapsed time is still correct.

The readout is HH:MM:SS.cs, refreshed at ten millisecond resolution and set in tabular figures so every digit occupies the same width. The number does not jitter and the layout does not shift while it runs.

Press Lap, or the L key, to mark a lap without stopping the clock. Each row shows the split — the time since the previous lap — next to the running total. That pair is what you actually need when you are timing intervals, sets, or repeated runs of the same task, and it is why a lap list is more useful than restarting the stopwatch each time.

Laps stay in the list until you reset, and the whole list can be copied as plain text into a note or a spreadsheet. Keyboard control is the fastest way to work: Space starts and pauses, L records a lap, R resets, and Esc cancels a pending reset. Every control is also a real button, so screen readers and switch devices reach it the same way.

The stopwatch is a client-side tool. The start timestamp, the accumulated milliseconds and the lap list are written to your browser's local storage under a single key, so a reload or an accidental close does not lose a running stopwatch. Nothing is uploaded and no account is involved.

The stopwatch itself is free, with no usage limit and no advertising interruption. When measured time needs to become hours worked, the hours calculator takes clock-in and clock-out times and returns totals and pay; the timesheet does the same across a full week or several people.