/3/4) : These are much easier to downgrade and often support "forced" downgrades to specific versions (like iOS 6.1.3 or 8.4.1) even without blobs. 64-bit (
If you have your SHSH blobs or are using a device that supports a tethered/forced downgrade, follow these steps:
for a newer device, use FutureRestore (not 3uTools) – 3uTools is unreliable for that.
Restoring an unsigned IPSW using 3uTools is a common goal for users looking to downgrade their iOS device or install a specific older firmware. However, because Apple uses digital signatures to control which iOS versions can be installed, this process is strictly limited by the device model and whether you have previously saved . Core Requirements for Restoring Unsigned IPSW

