Online Stopwatch
Start the stopwatch with one click and record laps as you go. It's accurate to a hundredth of a second and keeps counting even in a background tab.
How it works
Press Start and the stopwatch counts up from zero, accurate to a hundredth of a second. Tap Lap at any point to record a split without stopping the clock — each lap is logged with its own time so you can compare them afterward. Pause holds the running total, and Reset clears both the time and the lap list.
Use a stopwatch instead of a timer whenever you don't know the duration in advance and want to measure it: how long a task actually took, how fast a lap was, how long a call ran. A countdown timer is for the opposite case, when you already know the duration and want a warning at the end. If you're deciding between the two, ask whether you're measuring or limiting time.
Like the countdown timer, the stopwatch reads from the device clock rather than counting ticks, so it keeps accurate elapsed time even if you switch tabs or the browser throttles background timers. Laps and the running total are unaffected by backgrounding the tab.
Common uses
- Timing intervals or laps during a workout, such as sprint repeats or track laps.
- Tracking how long a task takes for billing or time-boxing freelance and client work.
- Timing a speech or presentation rehearsal against a target length.
Frequently asked questions
- What is a lap on a stopwatch?
- A lap records the time at that moment without stopping the stopwatch, so you can capture splits — useful for workouts, races and intervals.
- How accurate is the stopwatch?
- It measures to a hundredth of a second and is driven by the device clock, so pausing and resuming stays accurate.
- Does the stopwatch work offline?
- Yes, once the page has loaded. It runs entirely in your browser using the device clock, with no server calls needed to keep counting, so it keeps working if your connection drops.
- Can I run more than one stopwatch at once?
- Yes — open the stopwatch page in a second browser tab and each one runs independently. This is handy for timing two things in parallel, like two runners on different legs of a relay.