Stopwatch

When to use this

You're timing laps at the track and need to compare splits. You're running a science experiment and need precise elapsed time. You're a coach timing relay legs, or a debater tracking speaking time, or a game master managing turns. Anywhere you need to measure how long something takes — with the ability to mark intermediate points — a stopwatch with lap recording is the tool.

The lap feature is what separates a stopwatch from a timer. Recording splits lets you see not just total time, but pacing — are your laps getting faster or slower? The automatic green/red highlighting on fastest and slowest laps gives you that answer at a glance.

Good to know

Hundredths-of-a-second precision. The display updates at 60fps using requestAnimationFrame, giving you smooth, responsive time reading. For practical purposes, human reaction time to press the lap button adds ~150-300ms of variance, so the display precision exceeds your input precision.

Fastest and slowest laps are auto-highlighted. Green marks your best split, red marks your worst. After 3+ laps, this instantly shows whether you're fading or accelerating — no mental math needed.

Lap time vs. split time. Lap time is the duration of that individual segment. Split time (cumulative) is the total elapsed time at that point. Both are useful — lap time for pacing, split time for overall progress.

Copy all laps as text. One click exports your entire lap history as plain text for pasting into a spreadsheet, training log, or lab notebook. Much faster than writing times down by hand.

Quick Reference

Use Case	What to Track	Typical Precision Needed
Track/running laps	Lap splits, pacing	Seconds
Swimming intervals	Lap time per length	Tenths
Lab experiments	Reaction time, elapsed	Seconds
Cooking stages	Phase duration	Minutes
Debate/speech timing	Speaker duration	Seconds
Board game turns	Per-player time	Seconds