Dev Team have recently updated Redsn0w to jailbreak iOS 4.2.1. But remember only the iPhone 3G, older iPhone 3GS, and non-MC iPod touch 2G get the untethered jailbreak.


Other iDevices get a tethered jailbreak, which means that every time you reboot your iPhone, you will have to plug your iPhone in your computer, and launch Redsn0w to start your iPhone.

If you are an unlocker, do NOT update to iOS 4.2.1 yet. You will lose your chances of unlocking. Wait for PwnageTool, which should be updated pretty soon.

Below is a step by step guide showing you how to jailbreak your iPhone iOS 4.2.1 with Redsn0w.

Jailbreak iOS 4.2.1 Using Redsn0w 0.9.6b4 [How To] :


1) Download iOS 4.2.1 for your iDevice. Update/restore your iDevice to iOS 4.2.1 via iTunes.

2) Download Redsn0w 0.9.6b4 (download link at the end of the post).

3) Launch Redsn0w and browse for the firmware you downloaded in step 1.



4) Select to Install Cydia.

5) Make sure your iPhone is turned off and plugged in your computer. If it’s not, plug it in, then turn it off. Click next.



6) Hold the Home and Power button together for 10 seconds. Release the Power button while still holding the Home button for a few seconds.

7) Let Redsn0w complete its process. Once completed your iDevice will restart.



Now, you have successfully jailbroken your iDevice on iOS 4.2.1. If you have a newer iDevice such as the iPod Touch 4G, every time you reboot your iPne, you will have to launch Redsn0w and choose the “Just boot tethered right now” option to boot your iPhone.


There is currently no unlock for iOS 4.2.1 but we will keep you updated as soon as it is released.

If you have any query, feel free to ask in the comments section below.

Download Links :


Redsn0w 0.9.6 beta 4 (Mac)
Redsn0w o.9.6 beta 4 (Windows)