I recently did a factory reset to my phone and to my surprise, the operating system remained to the last updated version (6.0.0) and not the version I had when I bought the phone (5.0.0).

Why does this happen? Doesn't a factory reset reset the operating system too?

  • 1
    @beeshyams you're right.
    – papakias
    Commented Aug 17, 2016 at 17:28
  • That's fine - you got your answer from both :)
    – beeshyams
    Commented Aug 17, 2016 at 17:36

1 Answer 1


System updates overwrite /system. Factory reset wipes /data and /cache but doesn't touch /system. Simple as that.

  • can you backup /system to revert to an older version of android? Or is it more complicated than that? Commented Oct 31, 2017 at 16:37
  • 1
    If you have a TWRP backup of an OS older version, it can work - emphasis on "can" because it might not be compatible with the newer baseband, vendor, etc. partitions if the versions are too far apart.
    – Andy Yan
    Commented Nov 1, 2017 at 0:20

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