Multi Timer

Several named countdowns at once, which is the thing a single timer cannot do. Put the potatoes, the beans and the roast on separate clocks and see all three at a glance. When one finishes it keeps counting, so you can tell whether it went off ten seconds ago or ten minutes ago.

Lengths it understands

The length box takes whatever is natural to type: 20 for twenty seconds, 20 min, 1:30 for a minute and a half, 1h 15min, or 2m30s. If it cannot read what you typed it says so rather than guessing at a number.

Why it stays right in the background

Each timer holds the moment it will finish, not a number being counted down. Browsers throttle background tabs to roughly one timer callback a minute, so anything that decrements a counter loses time and finishes late. Working from the finish time instead means the reading is correct the moment you look at it, however long the tab was asleep.

The alarms are scheduled on the browser's audio clock as soon as a timer starts, which is not throttled either, so a timer that ends while you are in another app still sounds when it should.