Confirmed these settings on One+15 on OOS16 (based on Android 16).
Is it also the case for other Android brands?
P.S. I did use it before to turn off ads.
Weirdly, my very old Nexus 6P with the WiFi off, could lie untouched for weeks, with almost no battery depletion. Yet if I turn the WiFi on with near stock Android (meaning no messengers, tens of email accounts, etc, to constantly ping _something_), it just eats the battery within 24 hours tops. Perhaps that’s just the module itself, but I remember flashing LineageOS and having better savings. I have no real numbers to support that right now, although I still have the phone lying around somewhere and could test this some day.
Some Chinese/Taiwanese brands do it too, but most western brands don't seem to include a firewall.
None of the Samsungs I have owned so far had this feature and neither did my last Pixel.
1. App can't use mobile data in background
2. App can use mobile data in background except in Data Saver mode
3. App can use mobile data in background regardless of Data Saver mode
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For anyone doing comparisons, the literal settings appear under "Mobile Data Usage" as:
* [X] Background Data ("Enable usage of mobile data in the background")
* [ ] Unrestricted mobile data usage ("Allow unrestricted mobile data access when Data Saver is on")
