Why is my sleep data incorrect?

If you're seeing different values for sleep in Exist to what you see in Apple Health, or if certain sleep data is missing from Exist, such as REM, deep, or light sleep, this is usually due to confusion about the source of your sleep data.

Exist will only sync data from one sleep source per day. If you have multiple sources syncing sleep into Apple Health for the same day, for example the AutoSleep app plus the built-in iOS sleep tracking, Exist will use data from the first source it finds and ignore any other sources.

The only exception to this rule is that Exist will always prefer to sync data from a third-party source (i.e. an app or device not made by Apple) if it's available, even if you have also used the built-in sleep tracking launched in iOS 14.

Make sure you only have a single app or device syncing sleep data into Apple Health to ensure your data in Exist matches what you expect.

Learn how to check which apps or devices are syncing sleep data to Apple Health in this article.

If you find you're syncing sleep data from multiple apps or devices into Apple Health, and your sleep data in Exist doesn't match what you expect, this is likely to be the cause. To fix this problem, you'll need to delete the extra data from Apple Health so there's only one app or device syncing sleep data per day. You'll also need to turn off syncing sleep data from the extra app/device so this doesn't keep happening in future.

Note: Exist will also specifically ignore any sleep data from the built-in Clock app, which only provides time in bed data, and is therefore not accurate enough for our analysis. If you're using the Clock app, switch to another app for tracking your sleep if you'd like to sync it to Exist.