DFU mode your iPhone/iPod Touch/iPad

What is iPhone DFU mode?

DFU stands for Device Firmware Update. DFU mode is a state that your iPhone is put into where it can interface with iTunes but does not load the iPhone operating system or boot loader, this is what really differs DFU mode from recovery mode.

What is the use of DFU Mode?

The primary reason to access DFU mode on iPhone is to change the firmware on the device. This can serve to downgrade to a prior iPhone firmware and operating system, or to use a custom firmware that is required for a jailbreak or SIM unlock. For example, if you got iOS Device that is on OS 4 and decided you would rather have a prior version of the firmware on your device, you would need to do this through DFU mode.

Now that you know what is DFU mode and what it is for. Now you need to know how to get your iOS Device to DFU Mode.

How to enter iPhone DFU mode

Connect the iOS device to your computer and launch iTunes

Turn the iOS Device off (hold down the power button at the top of the iPhone)

Hold down the sleep/power button and home button together for exactly 10 seconds, then release the power button

Continue to hold down the Home button until a message appears in iTunes telling you an iOS device in recover mode has been detected

When you are in DFU mode your iOS Device screen will be in completely black

Now that you have your device on DFU mode you can now install custom firmware that you want. The most common use for DFU mode is to jailbreak

Note: If you see the restore logo, iTunes logo, or any message on the iPhone screen, your device is not in DFU mode but standard Recovery Mode. If this is the case, repeat the steps above until you enter into DFU mode successfully.

Now that you know how to put your device on DFU mode, you will need also know on how to EXIT on this mode. Below is the procedure how. 

Exit DFU mode on iOS Device

Exiting to DFU mode is very easy to do, that is to hold down the Home and sleep/power buttons on the iPhone while connected to iTunes. Then just hit the power button as and this should reboot the device as usual.