Originally Posted by Dragonsniper108
I have a samsung galaxy s2 and I am thinking of upgrading to a samsung galaxy s4. But I want to keep all the existing apps, data, messages, emails, etc... from the s2 to the s4, upon that the Rom itself. So is it possible to backup the s2 Rom then root the s4 and extract all the data from the backup onto the s4. Is that possible or will the firmware not allow it. So my question is "Is it possible to transfer a backup from a different phone onto an other phone?"
I don't think you should do what you want, because it can cause a lot of problems, if you just transfer data between different Android versions.
However, I think you can synchronize almost everything to yout Google Account (contacts, emails, phone numbers, installed apps, maybe even the data for them), so these informations will not get lost.
The only exception is SMS, but that can be solved too: there is an app on Google Play that can do that for you. (Name is "SMS Backup & Restore
" made by Ritesh Sahu
You backup SMS messages to XML file, keep it somewhere (for example microSD card), and from the new software you install this app again, and simply restore your backup. If something fails, that is no problem, since messages will be in XML files, and you can even read them with a text editor, so they will not disappear
So my advice is: backup SMS messages, and sync every other. But remember to do these before you do anything
that can erase these data (or before you want to take them to the new device).