This guide will give an overview of how to jailbreak your phone using the most common scenarios people are in. It will also cover some of the most frequently asked questions I receive through Twitter and email regarding the actual jailbreak process. If you have any further questions, feel free to post a comment here. If you've read Jailbreaking 101 and looked into the resources I've provided, you're probably already running a JB of your own. But we'll give quick and clean instructions for those of you who haven't quite gotten there yet. So, with out further ado, here they are.
Q. I'm running OS 4.2.1. I'm not an unlocker. How do I jailbreak?
A. Use Greenpois0n.
Q. Are there Mac and Windows versions of this program? And are both versions accessible?
A. Yes on both counts. I've heard nothing but successful reports from people who have managed to put their phone into DFU mode and get through the process.
Q. How do I use Greenpois0n?
A. The instructions simply say to hit jailbreak and follow the instructions on screen, but the instructions you receive can be a bit daunting. So we'll break it down.
When you hit jailbreak, you'll be prompted to enter DFU mode. Instructions on how to do this successfully will be discussed later, but for now, we'll explain the overall process. On screen, there will be a timer counting down. It's supposed to help you enter DFU mode. Great for sighted people, not so great for us. Working along with the timer can be done in the Mac version of the app, but it's not ideal. So how do we get past it?
Well, there are two ways to do it. The first is to enter DFU mode before you hit the jailbreak button. The second (Windows only) is to hit next after you hit jailbreak. This will autodetect your iPhone in DFU mode and make that timer go away. This second method assumes that you have not entered DFU mode before hitting the jailbreak button.
Q. I have little or no site. How do I enter DFU mode?
A. 1. Plug in your iPhone if not already plugged in. Power off your iDevice.
2. Hold down the sleep and home buttons at the same time. Press the sleep button a split second before you hit the home button, as your phone will need to power on before it can detect that you're holding sleep and home at the same time. Both buttons should be held for ten seconds.
3. Release the sleep button and continue holding the home button for another eight seconds.
4. Release the home button and continue.
Q. How do I know that I have successfully entered DFU mode?
A. Load up iTunes before you power off your phone. When your iDevice successfully enters DFU mode, iTunes will report that your device is in recovery mode and must be restored before it can be used again. This notification is false, as will be explained later, but seeing it is a clear indication that you are in DFU mode.
If you have some site, you will be able to see the screen change after holding home and sleep for six seconds. This is also a clear indication that the process is taking place smoothly.
Q. What is DFU mode, and what is it used for?
A. This article answers this question in a way that is easy for both the blind and sighted to understand.
Q. How do I know that I'm jailbroken?
A. You will see a "complete" notification when your phone is done with the jailbreaking process. Wait a minute or two for your phone to reboot, and you should hear Voiceover come on.
Q. How do I install Cydia on my phone after I've jailbroken with Greenpois0n?
A. The answer depends on whether you can see the loader icon on your home screen. Some people say yes;others say no. If yes, tap the loader icon and follow the instructions. If not, use Redsn0w to install Cydia. There are Windows and Mac versions. You will need the stock version of 4.2.1 for your iPhone model to tell Redsn0w what model and firmware you're using.
Q. I just installed Cydia with Redsn0w, and I see a notification that I am now running a tethered jailbreak. Did I just lose my untethered jailbreak?
A. No. Redsn0w was originally designed to be used with tethered jailbreaks. We are using Redsn0w as an alternative to using the loader icon provided by Greenpois0n. Greenpois0n is an untethered jailbreak. You did not just lose your jailbreak. If you're still scared, reboot your phone and see that all is well.
Q. Can I unlock with Ultrasn0w after jailbreaking my iPhone?
A. Yes, provided that you have a baseband that is supported by the latest Ultrasn0w.
Q. How do I tell what baseband my phone is currently on?
A. Go to settings/general/about. Your baseband will be listed as modem firmware. Voiceover will speak it as a date, but it is really a number. So for example, May 13, 2004 is really baseband 5.13.04.
Q. Where can I get any of the resources listed in this article?
A. Go here for jailbreak tools, starter packs, stock firmware, and more. In case you're wondering what I just linked to, it's my site, chicksdigmacs.net. If I don't have what you need, google is your friend.
Q. I'm running OS 4.1. How do I jailbreak?
A. Use Limera1n. I'm told it works in much the same way Greenpois0n does.
Q. I'm running OS 4.0.1 and below. How do I jailbreak?
A. Go to jailbreakme.com on your iDevice and follow the instructions.