Minutes after the official release of iOS 4.2.1, the folks at the iPhone Dev Team were able to roll out a compatible jailbreak tool for those enjoying the benefits of a hacked device. A compatible version of Cydia is unavailable for the latest iOS right now, but the jailbreak is, in all senses, a go for iPhone, iPod touch, and iPad using the Team’s redsn0w 0.9.6 beta 4.
Before users proceed with following the steps below, Pctipsbox would like to note that jailbreaking is not particularly encouraged.
Also, see this post for compatible devices and the particularities involving each device model with respect to this jailbreak. For example, this is a “tethered” jailbreak which, for some, may involve hassle they’d rather avoid. Go here to learn more about the drawbacks involved by a “tethered jailbreak.”
With all that out of the way….
Jailbreaking iOS 4.2.1 with Redsn0w 0.9.6b4 on Mac OS X (the steps should apply the same on a Windows PC)
Back up your device (in case anything goes wrong) and get your jailbreak ingredients ready:
Launch redsn0w, select your just-downloaded iOS 4.2.1 IPSW file for iPhone / iPod touch / iPad and click “next.”
If redsn0w is able to successfully identify your iOS firmware bundle, it will display the following message: “IPSW successfully identified,” as shown in the screenshot below. All you have to do now is click next.
Redsn0w will start jailbreaking the IPSW software bundle, as shown below.
As soon as the jailbreak is finished, you can employ some “goodies” that were recently introduced in redsn0w, such as installing custom logos. An option to install Cydia (currently incompatible with iOS 4.2.1), the App Store alternative for jailbreakers, is also presented. Tick whatever you want installed, and proceed to the following step by clicking “next.”
This step is important. You need to carefully follow the on screen instructions presented by redsn0w in order to put your device into DFU (recovery) mode. Don’t worry if you fail entering DFU mode on your first attempt. You can repeat the process.
After successfully entering DFU mode, redsn0w will automatically begin installing the jailbreak on your iPhone / iPod touch. As shown in the second screenshot down, the remainder of the jailbreak process will take place on your device which, at one point, should display the last two images below. Wait for your device to reboot.
You are jailbroken!
note: guide updated to include a link for those looking to learn more about the “tethered” nature of this jailbreak.
This article has a purely informational purpose and doesn’t, in any way, suggest that you should hack your Apple device.
Using hacks may render your device unusable, or may reduce the quality of your experience employing the respective device.
If you choose to download and install jailbreak tools, you will do so at your own risk. Unlocking / jailbreaking your iPhone / iPod touch / iPad / Apple TV may violate your warranty or the EULA with Apple and / or your cellular-service provider.