Stopwatch

Yes for everyday use: elapsed time is computed from performance.now() timestamps rather than counting timer ticks, so throttled tabs or slow frames cannot make it drift. Browsers guarantee performance.now() resolution to at least 1 millisecond, and the display shows centiseconds (hundredths of a second).

Click the Lap button or press L while the stopwatch is running. Each entry shows the lap number, that lap's time, and the total elapsed time at the moment you pressed it.

Space starts and stops the stopwatch, L records a lap, and R resets. Shortcuts are ignored while you are typing in a form field, so they never clash with typing.

Once you have 2 or more laps, the fastest lap is highlighted green and the slowest red, so you can spot your best and worst splits at a glance.

Laps live in memory for this browser session only. They are not stored in cookies or local storage and are never sent anywhere - resetting or closing the tab clears them.

Yes. Because elapsed time is recomputed from timestamps on every frame, switching tabs, minimizing the window, or a throttled frame rate will not corrupt the time. The display may update less often in a background tab, but the number stays correct.

The display shows centiseconds (MM:SS.CS) and extends to HH:MM:SS.CS once you pass one hour. The underlying timing is millisecond-precise.

No. All timing happens in your browser; nothing you do on this page is sent to a server or stored.