Using 2 Versions Previous Backup

[42545]

If possible, I plan to buy one of the iPhone 16s. There is a backup from my old iPhone 14 with iOS 16.5.1 in iTunes on my computer. Is there any problem in installing this on an iPhone with iOS 18?

Is installing a backup risky for the device?

 

[Apple_Robert]

You wont be able to install 16.5 on the new phone because Apple no longer signs 16.5 and the new phone will more than likely come with iOS 18.

 

[42545]

You wont be able to install 16.5 on the new phone because Apple no longer signs 16.5 and the new phone will more than likely come with iOS 18.

Yes, it will come with iOS 18, but when I load the backup, it will still be iOS 18 and the backup will be installed correctly, right?

 

[eyoungren]

Yes, it will come with iOS 18, but when I load the backup, it will still be iOS 18 and the backup will be installed correctly, right?

Yes. Your data in that backup will be restored to the device. Keep in mind that Apple stopped including apps in backups (AFAIK, even when using iTunes). All that is backed up as far as apps are concerned is a list of those installed. Once the backup is restored, your new iPhone will begin to download UPDATED versions of all apps on that list.

 

[arw]

Restoring an older backup onto an newer version of iOS is safe and intended by Apple.
After all, they want you to seamlessly use a newer device without having to set it up from scratch.
(I just set up a new iPad on iPadOS 17 from an iPadOS 15 backup. All perfect.)
As mentioned previously, you need an active internet connection for apps to be "restored" as they get downloaded.

What is indeed without any guarantee of working is restoring a newer backup onto an older version of iOS.
Meaning restoring a backup created under iOS 17 onto a device running iOS 16.
By default this is even blocked by Apple and you have to manually edit a parameter in the backup folder.