Lap Stopwatch

Run a live stopwatch and record individual lap times alongside the total elapsed time.

How to use Lap Stopwatch

1. Select Start Stopwatch; this tool needs no form inputs. 2. The browser runs the timer while the page remains open. Background throttling, sleeping devices and blocked sound can delay visible updates or alerts. Use Pause/Resume where shown and Reset to stop/clear it; this is not a guaranteed alarm or safety clock. Lap records elapsed values rather than a race-certified time. 3. Use Pause, Lap and Reset in the displayed stopwatch panel.

Why use this tool?

Use Lap Stopwatch when you need lap and total times. The browser runs the timer while the page remains open. Background throttling, sleeping devices and blocked sound can delay visible updates or alerts. Use Pause/Resume where shown and Reset to stop/clear it; this is not a guaranteed alarm or safety clock. Lap records elapsed values rather than a race-certified time.

How the calculation works

Measure elapsed browser-clock time and record laps. The browser runs the timer while the page remains open. Background throttling, sleeping devices and blocked sound can delay visible updates or alerts. Use Pause/Resume where shown and Reset to stop/clear it; this is not a guaranteed alarm or safety clock. Lap records elapsed values rather than a race-certified time. Live timer values show the current elapsed/remaining clock; the worked example describes the starting schedule.

Example

Starting example: Stopwatch starts at 00:00.

Practical tip

Check the lap stopwatch input and output convention before reusing the result.