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Required Reading

Only the iPhone 4, iPhone 4S, iPhone 5, iPhone 5c, iPad 2, iPad 3, iPad 4, iPad Mini 1G, and iPod Touch 5G on iOS 5 - iOS 10 are supported

Coolbooter allows you to dualboot any supported version of iOS on a select few of iOS device. Coolbooter is permanent, but can be removed through the Coolbooter app on the main OS.

This guide will require that you are already jailbroken on a supported OS listed above.

Installing Coolbooter

  1. Add the repo: using Cydia
  2. Download and install Coolbooter
  3. Tap Install
    • Choose any version of iOS you’d like
    • You can choose how much storage the new partition is allocated by tapping Storage
  4. Once your Coolbooter configuration is to your liking, tap I'm Ready
  5. Follow all onscreen prompts
    • We recommend you choose to jailbreak the new OS as Coolbooter-installed versions of iOS cannot be jailbroken except by Coolbooter itself
  6. After the Coolbooter has completed, reboot your device
    • You will need to jailbreak again if you are using a semi-untethered jailbreak
  7. Open Coolbooter
  8. Tap Boot
  9. When prompted to lock your device, lock it

If this doesn’t work, ask on the r/Jailbreak Discord Server for support.

To reboot back into your main version of iOS, reboot.