You can't unlock a Sprint iPhone 4 to work on a GSM network.
Why does this question get asked every day yet nobody knows that it's not going to happen?
I'm not here everyday. So its useless to unlock a sprint iphone 4 basically?
I don't even think a sprint iphone 4 exists. Sprint only had the 4S and iphone 5.
Sprint has an iPhone 4. It's only comes in the 8GB model.
Sprint can not be unlocked. Verizon can now, which is pretty new.