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Smart Web Apps Online Stopwatch

Online Stopwatch

Start, stop, lap, copy, and reset with an accurate time display.

Click Start to begin timing.
Elapsed time
00:00.00
Laps
# Lap time Total time
No laps yet.
Formula

Tool description

A stopwatch measures elapsed time from when you start until when you stop. Laps help you record split times without stopping the clock.

How to use

  1. Click Start.
  2. Use Lap to record split times.
  3. Click Stop to pause. Reset to clear.

Why it’s useful

  • Time workouts and intervals.
  • Track study or practice sessions.
  • Measure how long a process takes.

Use cases & interpretation

  • Intervals: use laps to measure repeats.
  • Efficiency: compare times across tasks.
  • Training: track improvements over time.

FAQs

It uses performance.now() for high-resolution timing, and calculates elapsed time from timestamps (not by counting ticks).