Caution: Jailbreaking your iPhone can be risky. If you use software to jailbreak, you are implicitly trusting the software developers. Be careful not to unplug your iPhone during the jailbreak process. Be sure to backup your iPhone & transfer purchases to iTunes prior to any and all jailbreak attempts. If you are using a laptop, be sure it is plugged into an AC power source. Double-check the software developer’s website to ensure you have the proper version of jailbreak software for your iDevice.

Overview

Jailbreaking and unlocking are two different things. Jailbreaking is a process that adds additional functionality to your iPhone, allowing you to install any software you like. Unlocking is a process that allows your iPhone to use any SIM card from any service provider. Some jailbreak applications only perform a jailbreak, some perform a jailbreak and unlock.  Check your local laws for the legality of these two processes.

There are two different types of jailbreaks, tethered and untethered. A tethered jailbreak requires you to plug your iPhone into a PC loaded with the same software you used to jailbreak it every time you want to boot your iPhone. An untethered jailbreak does not have this restriction. Obviously, an untethered jailbreak is more desirable.

I created this guide using a Verizon iPhone 4 running iOS 5.1.1. I used an application called Absinthe v2.0.4 by greenpois0n. Acording to greenpois0n’s website, this version will work for the following devices:

iPad 1, iPad 2, iPad 3 (iPad2,4 is now supported as of Absinthe 2.0.4)
iPhone 3GS, iPhone 4, iPhone 4S
iPod touch 3rd generation, iPod touch 4th generation

Prepare your iPhone

  1. Connect your iPhone to your computer and open iTunes
  2. Disable your passcode lock by going to Settings -> General -> Passcode Lock       then choose “Turn Pascode Off”. (don’t forget to turn this back on when finished jailbreaking)
  3. Disable encrypted backups if you’re using them (which you should be, and also turn these back on when finished jailbreaking)
  4. Transfer purchases to iTunes by right-clicking on the device in iTunes and selecting “Transfer Purchases”
  5. Back up your iPhone by right-clicking on the device in iTunes and selecting “Back Up”

    Caution: Be sure to back up successfully before proceeding to the next step, otherwise you will lose all data and settings on your iPhone. 

  6. Reset your iPhone by going to Settings -> Reset and selecting “Erase All  Content and Settings”

Get Absinthe

You can download Absinthe here: http://greenpois0n.com/downloads/

I used Absinthe 2.0.4 (Windows version) for this guide.

  1. Unzip the downloaded file
  2. Run absinthe-win-2.0.4.exe which will create a new folder called “absinthe-win-2.0.4”
  3. Open the absinthe-win-2.0.4 folder, and run the .exe file there to start the program

Perform Jailbreak

  1. Temporarily disable Anti-Virus
  2. Plug your iPhone into the computer (if it’s not already)
  3. Click the “Jailbreak” button 
  4. Wait for the process to finish, and be sure not to unplug the device. It should finish relatively quickly (mine took about 4 mins)
  5. When the process has finished, your iPhone will reboot, and you will see a new Cydia app (this indicates success)
  6. Now restore your backup by Right-clicking on the device in iTunes and selecting “Restore from Backup…”

You now have a jailbroken iPhone. Cydia is like another app store but without all of Apple’s ridiculous restrictions. Be wary though, Cydia apps are not subject to the scrutiny that App Store apps are.

Don’t forget to re-enable your Passcode Lock, encrypted backups, and Anti-Virus.