iOS 4.2.1 Jailbreak Released, Download Updated Redsn0w

Hot on the heels of the iOS 4.2 firmware release by Apple, the dev team have announced the iOS 4.2.1 Jailbreak for all devices with updated version of Redsn0w. All of this in less than 24 hours. Impressive right!


The jailbreak is based on Geohot’s limera1n bootrom exploit and the type of jailbreak depends on what device you have:

  • iPhone3G, older iPhone3GS, and non-MC iPod touch 2G: untethered jailbreak
  • More recent devices (iPhone 4, iPad, iPod touch 4G): tethered jailbreak (meaning if your device reboots, you’ll have to re-jailbreak)

iOS 4.2.1 Jailbreak download links:

  • Mac OS X
  • Windows

Their servers are quite overloaded at the moment for obvious reasons so you might have to be patient when you download Redsn0w.

Here’s what you will have to do beforehand.

  1. Backup SHSH blobs on iOS 4.1. Instructions here. This is important for future updates & untethered support.
  2. Update iPhone to iOS 4.2.1. Firmware download links here.
  3. Download Redsn0w from links above.

The picture of the unlock status is not so clear yet so those who rely on Ultrasn0w should wait right now. Those who have factory unlocked iPhones can proceed but make sure you backup SHSH on iOS 4.1.

Feel free to ask any questions via comments in case you have doubts regarding this jailbreak.