How to Downgrade iPhone 4S on iOS 5.1 / iOS 5.1.1 to iOS 5.0.1 Using Redsn0w

Jailbreak iPod Touch On iOS 4.2.1 Redsn0w

While we wait for pod2g to release his untethered jailbreak for iOS 5.1.1 for iPhone, iPad and iPod touch, Dev team has released a new version of Redsn0w (0.9.11b1) that allows iPhone 4S and iPad 2 users to downgrade their iOS device to iOS 5.0.1 so that they can use the Absinthe jailbreak to jailbreak their device.

This is a step-by-step guide for users to downgrade their iPhone 4S on iOS 5.1 or iOS 5.1.1 to iOS 5.0.1.

Some important points before we proceed:

  • This guide is meant for iPhone 4S users, we will publish a guide for iPad 2 users shortly.
  • This method will work only if you’ve saved your SHSH blobs for iOS 5.0.1 either using TinyUmbrella or had jailbroken your iPhone when it was running iOS 5.0.1 and launched Cydia at least once, which would have cached the SHSH blobs on its servers.
  • This method first updates iPhone 4S to the latest firmware and then downgrades it to iOS 5.0.1, so in the process it updates iPhone’s baseband. If you depend on Ultrasn0w then you should avoid using this method to downgrade.
  • Since the method restores your iPhone with iOS 5.0.1, you need to go through the process of setting up your iPhone from the backup, which will take sometime.
  • Please also make sure you’ve taken a backup of your iPhone either to iCloud or to iTunes.
Here’s the step-by-step instructions to downgrade your iPhone 4S using Redsn0w:
Step 1: Download Redsn0w for Windows from this link and Redsn0w for Mac from this link and save the application in a folder named “Redsn0w” on your desktop.
Step 2: Download iOS 5.1.1 firmware file and iOS 5.0.1 firmware file for iPhone 4S.
Please note both the firmware files are required for the downgrade process. If you’re downloading the firmware files using Safari then ensure that auto unzip feature is disable or use Safari or Chrome to download the firmware files.

Step 3: Please turn off your iPhone and connect it your computer.

Step 4: You will now need to put your iPhone into the DFU mode. You can follow these simple steps to put your iPhone in DFU mode:

(a) Hold the Power button on iPhone down for 3 seconds:

(b) Now simultaneously hold the Home button and keep the two buttons pressed for 10 seconds:

(c) Now release the Power button while keeping the Home button pressed until your iPhone’s screen goes black or iTunes pops up a message telling you that it has detected an iPhone in recovery mode.

Step 5: Double click the Redsn0w zip file and extract the application to the Redsn0w folder. Navigate back to the Redsn0w folder and launch the Redsn0w application. Please ensure that you have launched the latest version of Redsn0w (0.9.11b1).

Windows 7 users should run the exe in Windows XP compatibility mode (right-click on the Redsn0w exe and select Properties, then select the Compatibility tab and select Run this program in compatibility mode for Windows XP). Windows XP and Windows 7 users should run Redsn0w as ‘Administrator’ (right-click on the Redsn0w exe and select ‘Run as an Administrator’).

Step 6: Redsnow will report that your iPhone is connected in DFU mode (Connected: iPhone 4S (DFU mode)). Click on the Extras button, then click on the Even more button, followed by the Restore button.

Step 7: Click on the IPSW button, here browse to the location you had downloaded the iOS firmware files and select the iPhone4,1_5.0.1_9A405_Restore.ipsw file.

Step 8: You will be prompted to select the additional IPSW file. Click on the Ok button and browse to the location you had downloaded the iOS firmware files in Step 2 and this time select the iPhone4,1_5.1.1_9B206_Restore.ipsw file.

Step 9: You should now see the build of the iOS firmware file that you want to downgrade to next to the IPSW button, which will be iPhone4,1_5.0.1_9A405.

Step 10: In the next step, you need to retrieve the iOS 5.0.1 SHSH blobs for the downgrade process. If you’ve them stored locally then click on the Local button or click on the Remote button, if you want Redsn0w to download them from Cydia. If you had jailbroken your iPhone 4S while it was running iOS 5.0.1 and launched Cydia at least once then Cydia would have cached the SHSH blobs on the server. Redsn0w will show the progress bar as it Fetching blobs from the server.

Step 11: Once Redsn0w successfully downloads the iOS 5.0.1 SHSH blobs, it will start downgrading your iPhone 4S to iOS 5.0.1. It will stich blobs, restore to the hacked iOS 5.1.1 firmware and then restore to iOS 5.0.1.

Step 12: If it is successfully downgraded, Redsn0w will prompt you with a message informing you that your iPhone 4S has been successfully downgraded to iOS 5.0.1.

You will then need to setup your iPhone 4S from the backup. If you’ve any problem downgrading then check out this video tutorial by Jeff Benjamin:

You’re all set to jailbreak it using Absinthe jailbreak. If you need help then check our How to Jailbreak page for the link to our latest guide to jailbreak your iPhone 4S on iOS 5.0.1.

Update 1:

iPhone Dev team has released Redsn0w 0.9.11b2 to add support for iOS 5.0.1 build 9A406 so we’ve updated the post with the latest download links.

Update 2:

iPhone Dev team has released Redns0w 0.9.11b4, which includes some bug fixes, so we’ve updated the post with the latest download links.

Let us know how it goes in the comments.