Online Stopwatch with Laps

Yes. The stopwatch does not count ticks. It stores when you pressed start and works out the elapsed time from the clock each time it draws, so a browser that slows down background tabs cannot make it lose time. The numbers on screen may refresh less often while the tab is hidden, and catch up as soon as you return.

A lap time is how long each lap took on its own. A split time (the "Total" column) is the running time from the start to the moment you pressed Lap. The table shows both, plus how far each lap is from your average.

Yes. The start time and laps are saved in this browser, so a reload picks up the same run. Closing the tab does not stop the clock either: when you come back, the elapsed time includes the time you were away. Press Reset to clear it. Nothing is sent to a server.

Space starts or stops, L records a lap, and R resets. The shortcuts are ignored while you are typing in a field or have a button focused, so they never fight with the page.

It shows hundredths of a second and measures with the browser's monotonic clock, which is precise to well under a millisecond. In practice your own reaction time and the screen refresh rate (usually 60 times a second) are the limits, not the stopwatch.