Stopwatch
Online stopwatch with lap tracking
Track elapsed time, record laps, and review your fastest and slowest splits instantly in the same premium layout as the other upgraded tools.
Live stopwatch display
Press start to begin your first lap.
Everything you need in a stopwatch
Centisecond Precision
Updates 60× per second using requestAnimationFrame for smooth, accurate timing down to 1/100th of a second.
Unlimited Lap Recording
Tap Lap at any checkpoint to log a split. Each entry shows the lap split time and total elapsed time side by side.
Fastest & Slowest Highlights
Your best lap glows green, slowest in red — instant performance insight without any manual analysis.
Persists Across Reloads
Laps and current time are saved to localStorage automatically. Close the tab, come back — nothing is lost.
Works Offline
Once loaded, the stopwatch runs entirely in your browser. No internet connection needed mid-session.
Mobile-Optimised
Large tap targets and a responsive layout make it comfortable on a phone, tablet, or desktop monitor.
How to use the stopwatch
Open the page
Navigate to clockunit.com/stopwatch — no login, no download. The tool is ready instantly.
Press Start
The timer begins counting from zero with centisecond accuracy. The display turns green to confirm it's running.
Record laps
Hit Lap at every checkpoint. The table tracks individual splits and highlights your fastest and slowest.
Pause & Resume
Pause freezes the clock without losing a millisecond. Resume picks up exactly where you left off.
Reset when done
Click Reset to clear the timer and all laps, ready for the next round or session.
Who uses this stopwatch?
Sports & Fitness
Interval runs, swim laps, cycling sprints, gym sets.
Education & Science
Reaction times, experiment durations, timed presentations.
Work & Productivity
Focus blocks, meeting lengths, billable task durations.
Cooking
Time multi-step recipes using laps for each stage.
Dev & Testing
Benchmark UI interactions and run manual performance tests.
Games & Challenges
Tournaments, speedruns, and timed puzzle challenges.
Why use ClockUnit instead of an app?
A dedicated stopwatch app needs installation, storage space, and often requests unnecessary phone permissions. ClockUnit runs right in your existing browser — no install, no tracking, nothing leaves your device. Works on Windows, macOS, Linux, Android, and iOS.
Unlike a phone stopwatch that disappears when you switch apps, ClockUnit stays running in its tab and automatically saves your laps to localStorage — so even an accidental reload won't lose your data.
Frequently asked questions
Stopwatch Online with Laps and Precision splits
Our online stopwatch with laps is built for accuracy and mobile responsiveness. Track splits and elapsed time for sports, scientific experiments, or coding sprints. With one-tap lap recording and high-visibility digital numerals, it’s the most efficient way to track precision time periods on any device. Start your free timer session now and keep your records organized.