Understand the result
How to use the online stopwatch
Measure elapsed time, pause and resume the same session, and record lap timestamps without installing an app.
Formula or method
Elapsed time is the current browser performance timestamp minus the stored start timestamp, plus any previously paused duration.
Worked examples
Time a focused task
Start before the task, press Lap at each checkpoint, and pause when the work ends.
Record exercise intervals
Use Lap after each circuit while the main elapsed timer continues running.
Pause an interruption
Pause during a break and resume later to measure active time rather than total clock time.
Frequently asked questions
Will the stopwatch keep running when I switch tabs?
Elapsed time is based on the browser performance clock, so it normally remains accurate even when visual updates slow in a background tab.
What is the difference between Pause and Lap?
Pause stops elapsed time. Lap records a checkpoint without stopping the main stopwatch.
Does refreshing the page preserve my laps?
No. Refreshing or closing the page clears the current stopwatch and lap list.
How precise is the displayed time?
The display shows milliseconds, but actual timing precision depends on the browser, device and power-saving behavior.
Limitations
Refreshing or closing the page resets the session.