Is it possible to downgrade?

[passingby]

Hello,

Just upgraded to Android 4.3 and didn't like it at all.

Is there a way to downgrade to a previous version? In my case that was factory version Android 4.1.2, and it was so much better.

I know there is an unofficial tool for that called FLASHTOOL, but I'd still need to download the firmware from somewhere.

Where can I download the firmware? Is it safe to download it from an unofficial source? (I mean, what if it contains some additional malicious functionality that steals data, for example..... ).

[passingby]

Or maybe options like Hard or Factory Reset could help?

[Thommo]

If it did then you wouldn't be able to use it without unlocking your bootloader - When an official firmware is modified it becomes a .img file and not the intended .ftf file,

A factory reset won't downgrade you or a system repair - You will need the .ftf firmware file and Flashtool as you said

[passingby]

Thanks. So there is no way someone can create a "fake" *.ftf firmware with some modified functionality?