Apple finally released the final version of iOS 10.2 to the public which includes several new features and improvements. If you’ve installed iOS 10.2, but want to downgrade back to iOS 10.1.1, because you want to prepare for the iOS 10.1.1 jailbreak or you found it too buggy or it is draining battery life then we’ve covered.
Downgrading from iOS 10.2 to iOS 10.1.1 is quite easy as Apple is still signing the iOS 10.2 firmware.
-You will be able to downgrade back only to iOS 10.1.1, which is the latest version. You cannot downgrade to the previous versions as Apple has stopped signing the older iOS firmware files.
-You will be able to downgrade to iOS 10.1.1 only till Apple is signing the iOS 10.1.1 firmware file.
-It is important to take a backup of your iOS device to iCloud or using iTunes so you can restore from the backup if something goes wrong.
-Please note that the process involves wiping your device, and then restoring it from a backup, so it can take some time depending on how much data needs to be recovered and your internet connection (if you’re restoring from an iCloud backup).
Check real-time signing status
To find out if Apple is still signing the firmware file, check this website. Green rows with a tick mean that Apple is still signing the firmware file, and you can downgrade from iOS 10.2 to iOS 10.1.1.
How to Downgrade from iOS 10.2 to iOS 10.1.1
Download the iOS 10.1.1 firmware file for your device. The iOS 10.1.1 firmware file for iPhone 6s Plus is iPhone_5.5_10.1.1_14B150_Restore.ipsw. Accordingly, download the appropriate firmware file from the iOS firmware file download page for your iPhone, iPad or iPod touch.
If you’re downloading the firmware file using Safari then ensure that auto unzip feature is disabled or use Chrome or Firefox. Alternatively, renaming the .zip file as .ipsw file should also work.
You now need to put your device in DFU mode (if you want to find out what it means check this post for more details):
-Plug your device into your computer.
-Turn off the device by holding the Sleep/Wake or Power button and swiping it off.
-Hold the power button for 3 seconds.
-Begin holding the Home button without releasing the Sleep/Power button for 10 seconds.
-Release the power button and continue holding the home button until you get a popup from iTunes that it has detected that your device is in Recovery mode.
Click on the Ok button.
Hold the Alt/Option key on the Mac or Shift key in Windows on your keyboard and click on the Restore iPhone… (iPad/iPod touch…) button. Note: If you directly click on the Restore iPhone button without holding the Alt/Option key on the Mac or Shift key in Windows will result in restoring your device back to iOS 10.1.1.
Select the iOS 10.1.1 IPSW file you had downloaded earlier.
Then click on the Restore and Update button to continue.
In the next screen, it will give you information about the iOS 10.1.1 update. Click on the Next button, followed by the Agree button to continue.
iTunes will now verify the software and install it on your device. It should take around 10 minutes.
After it is successfully restored to iOS 10.1.1, you should see the white ‘Helo’ screen. Follow the on-screen instructions to set up your device, and restore your device from the archived backup you had made before installing iOS 10.1.1 to restore your personal data.
That’s it. Your iPhone, iPad or iPod touch should now be successfully downgraded from iOS 10.2 to iOS 10.1.1.
If you get the error message “This device isn’t eligible for the requested build” then it is probably because you’ve downloaded the wrong firmware file for your device.