Online Stopwatch with Laps, Splits, and Fullscreen
Time anything to the hundredth of a second — a run, a study session, a speech, or a lab experiment. UtilHub's free online stopwatch records unlimited laps and splits, highlights your fastest and slowest lap, and shows the average, so progress is visible at a glance. Go fullscreen for a big display across the room, or control it from the keyboard with Space, L, and R. Time is measured against your device's clock instead of being counted frame by frame, so it stays accurate in a background tab, and a running stopwatch keeps running even if you reload the page or close the browser. When you finish, copy the laps or download them as a CSV file for a spreadsheet.
How to use Stopwatch
- Press Start, or the Space bar, to begin timing.
- Press Lap, or L, at the end of each lap to record a split.
- Press Pause to stop the clock and Resume to continue from the same time.
- Review your laps — the fastest and slowest are labeled.
- Copy the laps or download a CSV, then press Reset to start over.
Features
- Laps with analysis — Unlimited lap and split times, with the fastest, slowest, and average lap shown automatically.
- Accurate in the background — Timing uses the system clock, so a throttled tab, a locked screen, or a reload never loses time.
- Fullscreen and shortcuts — A large display for classrooms and gyms, plus Space, L, R, and F keys.
- Export your times — Copy laps to the clipboard or download a CSV with lap and total times in seconds.
Frequently Asked Questions
Does the stopwatch keep running if I close the tab?
Yes. The start time is saved in your browser, so when you come back to the page — after switching tabs, reloading, or even closing the browser — the stopwatch shows the correct elapsed time and keeps counting. Your laps are kept as well. Press Reset to clear the saved time.
How accurate is an online stopwatch?
The display refreshes about 60 times a second and elapsed time is calculated from the device clock with sub-millisecond resolution, so the stopwatch itself does not drift. In practice, accuracy is limited by your reaction time when pressing the button, typically 0.1 to 0.25 seconds, which is why coaches often average several attempts.
What is the difference between a lap time and a split time?
A lap time is the length of one lap on its own, measured from the previous press of Lap. A split time, shown here as Total, is the cumulative time from the start to that press. A runner doing 400-metre repeats watches lap times; a marathoner checking pace at each kilometre watches splits.
Can I use the stopwatch on my phone?
Yes. The buttons are sized for touch, and while the stopwatch runs the page asks your phone to keep the screen on where the browser supports it. Install it from this page to open it like an app from your home screen, and use fullscreen for a large display during workouts.