Stopwatch

About Stopwatch

An online stopwatch counts up from zero and measures elapsed time to the millisecond. Start, stop, and reset with a click or the spacebar, and record lap splits to time individual segments, with the fastest and slowest laps highlighted. It runs entirely in your browser with nothing to install.

Frequently asked questions

Does the stopwatch keep running in a background tab?

Yes. It keeps time from real timestamps rather than a tick count, so the elapsed time stays accurate even if the tab is inactive or your screen sleeps.

What are lap splits for?

Laps record split times without stopping the clock — useful for timing repeated intervals like workout sets or running laps. The fastest split is highlighted in one color and the slowest in another so you can compare at a glance.

Can I control the stopwatch with the keyboard?

Yes. Press Space to start or stop, L to record a lap, and R to reset — fast, hands-free timing with no need to aim at a button.

What's the difference between the stopwatch and the timer?

The stopwatch counts up from zero to measure how long something takes. The timer counts down from a duration you set and sounds an alarm at zero. Use the stopwatch to time an event, the timer to be alerted after a set amount of time.