Redsn0w 0.9.6rc9, the jailbreak support all iOS devices except iPad 2.
NOTE: Users who rely on ultrasn0w unlock MUST stay away from Redsn0w.
iOS jailbreaking is a process that allows devices running Apple's iOS (also known as iPhone OS prior to iOS 4.0) operating system (such as the iPad, iPhone, iPod Touch, and recently Apple TV) to gain full access (root access) to unlock all features of the said operating system, thereby removing limitations imposed by Apple. Once jailbroken, iOS users are able to download additional applications, extensions and themes that are unavailable through the official Apple App Store, via installers such as Cydia, one of a number of current means for older iPhones. A jailbroken iPad, iPhone or iPod Touch running iOS can still use the App Store and iTunes and other normal functions, such as making telephone calls. Jailbreaking is similar to rooting an Android device.
At its core, jailbreaking a device gives access to its root filesystem, allowing modification and installing Third-party software components. This gives the user more control over the device and may allow features that were previously unavailable without jailbreaking.
Under the DMCA of 2010, jailbreaking is legal in the United States, although it voids Apple's device warranty. It is also legal in many other countries including those of the EU. The jailbreaking process, however, can be quickly and easily reversed by restoring the operating system through iTunes. Cydia creator Jay Freeman estimates that more than 10% of all iPhones are jailbroken.
Download iOS 4.3.1 for your device (download links at iPhone Firmware Collection)Update/Restore to iOS 4.3.1 firmware using the IPSW file via iTunes New Version for Windows or Mac.Start Redsn0w and point it to the official iOS 4.3.1 firmware file.
Download Redsn0w 0.9.6rc9 (Windows)
Download Redsn0w 0.9.6rc9 (Mac)
Now simply select “Install Cydia” and click “Next”.
Now make sure your device is both OFF and PLUGGED IN to the computer before you click “Next”
At this stage you will be presented with a screen where you will be guided on how to enter DFU mode. Quickly hold “Power” button and then while holding the “Power” button, you will now have to hold “Home” button too. Now after few seconds release “Power” button but keep holding “Home” button until installation begins..
Wait shortly. Once done, your iPhone, iPad or iPod touch will restart automatically and you will find it fully jailbroken (untethered) on the latest iOS 4.3.1 firmware.