Privacy

This page describes sleeptimer, the calculator at https://getsleepcalculator.com. The only preference the app saves is how many minutes you usually need to fall asleep.

Stored on this device

That number is a whole number from 5 to 60, in steps of 5. Until you change it, the calculator uses 15. The browser stores it under the key sleeptimer.onset. If storage is blocked, the same number stays in memory for the open tab and is dropped when the tab closes. Another open tab of this site can pick up a saved change. There is no account, so the number is never filed under a name, an email address, or a sign-in.

What the address holds

Calculate writes two fields into the address on the page you are using: mode (bed or wake) and at (a 24-hour time such as 06:30). Those fields let a refresh show the same plan. A request for that address includes them, the way any page address does. Back removes the fields. sleeptimer does not ask you to create a profile for them.

What the calculator leaves alone

The fall-asleep setting is read and written in this browser. The app has no microphone, no camera, and no motion sensor, and it does not connect to a watch or other wearable. It does not record a night of sleep. The times on the cards are minutes added and subtracted on the page. Read the about page for what the calculator is for, and what it refuses to decide.