What is a Stopwatch and Timer?
Two of the most reached-for tools on the web, and neither needs an account, an app or a page full of adverts.
The stopwatch runs to hundredths of a second and records laps. The timer counts down from any hours, minutes and seconds you set and sounds a tone when it reaches zero.
Both keep running while the tab is in the background, because the elapsed time is measured against the system clock rather than counted in frames. Minimising the window or switching tabs does not slow them down, which is the failure most browser timers have.
Frequently asked questions
Does it keep time if I switch tabs?
Yes. Elapsed time is computed from the system clock, not accumulated frame by frame, so a background tab stays accurate. Browsers throttle timers in background tabs, which is why a naive implementation drifts.
Will the alarm sound if the tab is in the background?
Usually yes, though some browsers block audio until you have interacted with the page. Starting the timer counts as that interaction.
How accurate is the stopwatch?
It displays hundredths of a second. Your reaction time on the start and stop buttons will be a larger source of error than the clock.
Is anything saved?
No. Nothing leaves the page and nothing is stored once you close it.