Does Restoring an iPhone backup restore the iOS version as well?

[Partron22]

Probably already been asked, but I'm new to this iPhone stuff, and have few search skills in this subforum.
I'm running iOS 8.4.1.
Did a backup to my Mac.
Turned off auto updates, but sooner or later I'm going to have to give iOS 9 a try.

Will restoring from backup return me to iOS 8, or is there something else I need to do as well?

 

[maflynn]

Generally no, there's no way to downgrade to an older OS.

 

[Partron22]

Surely I can Jailbreak, as on my Nexus 7, downdate from there, then unjailbreak at the lower OS, or are we really totally locked out on this?
Perhaps through the Dev program?
I need the iPhone, but this inflexibility leaves me less than pleased.
-Thanks for the answer, sad as it is. If it's really the case, I guess I'll wait for 9.2 or so before taking the leap.
Sorry for wrong forum, I've never had an iPhone before, so am sort of flailing.

 

[maflynn]

No because apple does not permit it. Its their product, it doesn't matter if its jailbroken

 

[Partron22]

How to Downgrade from iOS 9 Back to iOS 8.4.1

A few things to keep in mind here: downgrading only works as long as Apple signs the prior version of iOS, which is typically a short window. Also, you can’t restore an iTunes backup from a new version of iOS to an older version of iOS, so you may lose your data by doing this.

So 'try before you buy' is possible. However you need to be fairly quick about it, and be willing to accept losses.