Stopwatch

Use calendar math with the assumption visible

Use it for quick manual timing, QA checks, presentation practice, exercise intervals, cooking tests, or measuring how long a task actually takes. The stopwatch tracks elapsed milliseconds, pause state, and lap snapshots inside the current tab.

The stopwatch stores a start timestamp, adds any previously elapsed time, and updates the display every tenth of a second while running. Lap output lets QA or practice sessions keep intermediate checkpoints rather than only a final time.

Limits and local processing

It runs in the current browser tab; background throttling can reduce display update frequency. Timing state lives in the browser tab and resets when the page is refreshed. Do not rely on it where background-tab throttling or system sleep could affect official timing. Laps are kept as separate rows so repeated trials can be compared without opening a spreadsheet or notes app. It is intentionally lightweight.