Stopwatch & Alarms
Online Stopwatch
A precise online stopwatch with lap times.
How to use the online stopwatch
- Press Start or the Space key.
- Press Lap (L) to record split times.
- Press Reset (R) to clear, or copy laps as CSV.
Start, pause and lap with millisecond precision. Keyboard shortcuts keep your hands free.
Tips
Use laps to compare repeated efforts, such as practice runs or student presentations, without stopping the clock. Copy the laps as CSV to paste them into a spreadsheet.
Frequently asked questions
How precise is the stopwatch?
It shows milliseconds and is computed from timestamps, so display delays do not cause drift.