As the untethered jailbreak for iOS 6 is still unavailable, many of people choose to revert back to iOS 5.1.1 after upgrading our devices to iOS 6. Fortunately, there is a way to downgrade iOS 6 to 5.1.1 for those who are looking for an untethered jailbreak.
You will need to save SHSH Blobs for iOS 5.1.1 prior to downgrading from iOS 6. What’s more, if you had jailbroken the device when it was running on iOS 5.1.1, then you can downgrade it. If the device has never been jailbroken before, then it can’t be downgraded.
- Supported Devices: iPhone 4, iPhone 3gs, iPod touch 4G
- Unsupported Devices: iPhone 5, iPhone 4S, iPad 3
Preparations:
Firstly make sure to back up the device in case you may loss any important information during the downgrading. If you don’t need the backup, please just skip step 1&2 and start from step 3.
Step 1: Download the latest iTunes
If you have already installed iTunes, make sure you have updated it to the latest version.
Step 2: Back up your device
- Plug into your device on your Mac and enter iTunes
- Right click the device name in the sidebar list shown below
- Click Back Up and wait for the sync to finish
Step 3: Download required tools
Download the relevant iOS 5.1.1 IPSW firmware:
Download the latest RedSn0w:
- RedSn0w 0.9.14b2 for Mac
- RedSn0w 0.9.14b2 for Windows (Run as administrator)
Ready to Go!
Turn off your device and connect it to computer, then put the device running iOS 6 into DFU mode following these steps:
- Hold down the Power button on iOS device for 3 seconds.
- Without releasing the Power button, simultaneously hold the Home button and keep them pressed for 10 seconds.
- Now release the Power button while keeping the Home button pressed or up to 15 seconds.
Step 1: Open RedSn0w and click on "Extras" button.
Step 2: Click on "SHSH blobs" button.
Step 3: Click on "Stitch" button.
Step 4: Click on "IPSW" and select iOS 5.1.1 IPSW firmware which you have downloaded in Preparations.
Step 5: Click on "Local" and select the .shsh file, or please check "Cydia" to locate SHSH blobs if you have stored the file in Cydia.
Step 6:
After that, RedSn0w will start to integrate the SHSH blobs into the firmware to create Custom FirmWare. It’s the key of the downgrade.
Step 7: Switch to the Extras interface of RedSn0w by clicking twice on "Back" button, then click on "Pwned DFU" to enter pwned DFU mode.
Step 8:
Open iTunes, it will detect that your device has entered into recovery mode. For windows users, hold "Shift" on the keyboard and check "Restore". For Mac users, hold "Option" and check "Restore". Then select the created Custom FirmWare.
Step 9: iTunes begins restoring your device, it is normal to get iTunes Error-1 message. 
Step 10: Now you need to reopen RedSn0w and click on Extras > Recovery Fix, and your device will enter DFU mode to fix the recovery. 
When it is finished, you should have already downgraded iOS6 to iOS5.1.1 on your iDevice.
In addition, downgrading the iPad 2 from iOS 6 to iOS 5.x requires the saved SHSH blobs for both 5.x and 4.x. If you are currently using iPad 2 running on iOS 6 and want to downgrade it, please learn more here.