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Online Stopwatch with Lap Times

Online stopwatch accurate to 10ms, lap recording, fullscreen mode, Space/L/R shortcuts. Perfect for classrooms, experiments, and sports. Works offline.

All tools

00:00.000

00:00

Shortcuts: Space = Start/Pause · L = Lap · R = Reset

Stopwatch with 10ms precision, lap recording, fully offline. Great for experiments, sports, classroom timing.

When to use an online stopwatch

Classroom: time student tasks, presentations, group games.
Experiments: time chemistry/physics reactions — accurate to 10ms.
Sports / Training: lap times for running, swimming, jump rope.
Cooking: time boiling, simmering, fermenting.
Presentations / Interviews: track total time + each section (lap).

Features

10ms precision — built on performance.now(), no drift over time.
Lap times: hit "Lap" to record splits — auto-shows fastest / slowest / average.
Fullscreen: tap ⛶ for projector or classroom display.
Keyboard shortcuts: Space = Start/Pause, L = Lap, R = Reset.
Offline-ready: works without internet. Great on a classroom iPad.

Stopwatch vs Timer

A stopwatch counts up from zero (how much time has passed). A timer counts down from X to zero (how much time remains). Need a countdown? Use the Classroom Timer.