The Privacy Policy is the main explanation of our data practices. This page gives the short, practical version.
What it reads
- Sleep analysis: time asleep, in bed and sleep stages.
- Heart and breathing: heart rate, HRV, blood oxygen, respiratory rate, resting heart rate, wrist temperature and breathing disturbances, when recorded.
Last night's readings are compared with up to 30 earlier nights. A usual needs three earlier nights with that value; before then the app labels the reading New.
Read only, on your device
The app reads from Apple Health and does not write to it. The analysis happens on your iPhone; there is no account or server receiving health readings. You can change permissions in Apple Health. Deleting Landmark Sleep removes its local app data, but not your original Apple Health records.
When readings are missing
A sleep source without stage data shows asleep and awake. Heart, HRV, blood oxygen and breathing readings require an Apple Watch worn to sleep. Missing values say No data; they are never filled with invented values.