Timer & Stopwatch

What does this tool do?

Two things in one page: a countdown you set in minutes and seconds, and a stopwatch that counts up and takes laps. The Pomodoro presets — 25/5, 50/10, 15/3 — are countdowns with a work length that people actually use.

Writing a duration

The box accepts the ways people write times, not one format you have to guess:

• 25:00 — minutes and seconds, as on a stopwatch.
• 1:05:00 — hours, minutes and seconds when there are hours.
• 1h30m, 90m, 45s — with units, glued or spaced.
• 90 — a plain number is seconds, which is the one case worth spelling out.

Why it can run offline

The countdown uses your tab’s clock and nothing else, and it counts with timestamps rather than by adding up ticks: browsers throttle background timers, and a timer that adds up ticks ends up short. Nothing is sent anywhere and no notification permission is requested; if the tab is closed, the timer goes with it.

Keep in mind

A timer that only exists in a browser tab cannot survive the tab closing, and this one does not try. If you need to be told in half an hour while you do something else on another device, use the clock on your phone — this is for the times you are sitting in front of the screen.