Why can't Pillow find any sleep stage data information?
This message appears only if you have selected to use Apple Health as the source of sleep stage data instead of Pillow. Pillow will use Apple Health as a reference if this option is enabled. Apple Health will not always generate sleep stage data. If Pillow can't find Sleep Stage data, it will display an error message.
Does Apple Health always generate sleep stage data?
No. Apple Health can generate sleep stage data only if you have installed watchOS 9 or newer on your device and enabled "Sleep" mode.
Even if the above conditions are met, Apple Health may still not generate sleep stage data for reasons we don't know. In this case, we recommend contacting Apple or using Pillow's Sleep Stage data.
How can Apple Health generate sleep stage data for a specific day?
Open the Health App on your iPhone
Tap on the "Browse" tab at the bottom
Select "Sleep"
Can I switch back to Pillow as the source of the Sleep Stage analysis?
Yes, you can switch between Sleep Stage data sources at any time. To do so:
Launch Pillow on your iPhone
Tap on the Settings icon in the top right corner
Scroll to find the section named "Sleep Tracking."
Tap on "Sleep Stage Data" → Select "Use the sleep stage data produced by Pillow."