Redsnow is easy to use, it is available for Windows and Mac OS. Pwnagetool can be used to create custom ipsw and preserve baseband, it supports Mac OS only.
Ultrasn0w doesn’t work on iOS 4.3.1 yet (even with iOS 4.3.1 + old baseband). The fix will be available soon. Here’s a warning from DevTeam for unlockers:
ultrasn0w users don’t update yet! We need to first release an update to ultrasn0w that fixes some incompatibilities when FW 4.3.1 is used on the older basebands supported by ultrasn0w. And remember once we do fix ultrasn0w for 4.3.1 (we’ll announce it here and on twitter), you must only get there via a custom IPSW from PwnageTool, Sn0wbreeze or xpwn! Don’t ever try to restore or update to a stock IPSW, or you’ll lose the unlock!
Redsnow is easy to use, it is available for Windows and Mac OS. Pwnagetool can be used to create custom ipsw and preserve baseband, it supports Mac OS only.
Ultrasn0w doesn’t work on iOS 4.3.1 yet (even with iOS 4.3.1 + old baseband). The fix will be available soon. Here’s a warning from DevTeam for unlockers:
I0n1c posted the video below on YouTube. Current untetheredjailbreak is alpha, it is not finished. So no due dates yet. We do not know when untether will be available for public. We’ll keep you updated.
Apple will soon disable restoring to iOS 4.2.1 for iPad and iPhone. In order to preserve jailbreak and unlock save your SHSH keys now! 4.3b keys might also help you in future untethered jailbreak.
You can do that using TinyUmbrella utility. Download it for Mac or Windows here. Just run it and push “Save ALL SHSHs” button.
The other way is to save SHSHs via Cydia. Run Cydia and make sure the keys are saved (green line on the top).
Untethered iOS 4.2 jailbreak GreenPois0n has just been upgraded to version RC6. New version includes support for the Apple TV 2G. GreenPosi0n will give your Apple TV an untethered jailbreak and will also install the popular NitoTV software on it. RC6 also fixes emulator issues. So if you had problems with RC5 go ahead and try this one. You can also apply RC6 over RC5 without restoring.
You can download the latest GreenPois0n version here.
These are step-by-step instructions on how to jailbreak iOS 4.2.1 on iPhone 3GS, iPhone 4, iPad, iPod Touch 2G, iPod Touch 3G, iPod Touch 4G using Greenpois0n for Windows. Tutorial for Mac OS X users is available here. All the steps are the same for all devices, we will cover iPhone.
Greenpois0n has been updated to support the iOS 4.1 and iOS 4.2.1 firmware. Use Limera1n if you want to jailbreak iOS 4.0, iOS 4.0.1, iOS 4.0.2.
Remember: Greenpois0n recommends a clean restore before continuing.
Unlockers: do not update to iOS 4.1 or iOS 4.2.1 if you need the unlock. Ultrasn0w does not support that baseband yet. The only exception is the iPhone 4. Experienced users can also try update to iOS 4.2.1 without upgrading your baseband by using TinyUmbrella. Start TSS Server->Start iTunes->Plug in your iPhone->Restore 4.2.1->Error 1013->Put phone into DFU Mode->Launch Greenpois0n.
We are not authors of this app. We do not promise that everything will go well, use this tutorial at your own risk.
These are step-by-step instructions on how to jailbreak iOS 4.2.1 on iPhone 3GS, iPhone 4, iPad, iPod Touch 2G, iPod Touch 3G, iPod Touch 4G using Greenpois0n for Windows. Tutorial for Mac OS X users is available here. All the steps are the same for all devices, we will cover iPhone.
Greenpois0n has been updated to support the iOS 4.1 and iOS 4.2.1 firmware. Use Limera1n if you want to jailbreak iOS 4.0, iOS 4.0.1, iOS 4.0.2.
Remember: Greenpois0n recommends a clean restore before continuing.
Unlockers: do not update to iOS 4.1 or iOS 4.2.1 if you need the unlock. Ultrasn0w does not support that baseband yet. The only exception is the iPhone 4. Experienced users can also try update to iOS 4.2.1 without upgrading your baseband by using TinyUmbrella. Start TSS Server->Start iTunes->Plug in your iPhone->Restore 4.2.1->Error 1013->Put phone into DFU Mode->Launch Greenpois0n.
We are not authors of this app. We do not promise that everything will go well, use this tutorial at your own risk.
Step One
Open your web browser and download the latest Windows version of GreenPois0n from here.
Step Two
When prompted save the download to your desktop.
Step Three
Double click the downloaded gp_win_rc5_b2.zip file then drag the greenpois0n.exe file to the desktop. Double greenpois0n.exe from the desktop to launch the application
Step Four
Connect your iPhone to the computer, power it off. Then click the large Prepare to Jailbreak (DFU) button in greenpois0n app.
Step Five
You will now be instructed on how to place your iPhone into DFU mode.
You will be asked to press and hold the sleep button (power button) for 3 seconds.
Now continue holding sleep button and and press home for 10 seconds.
Release sleep button and continue holding the home button. Do not release the Home button at this point!.
Step Six
Once your iPhone is successfully in DFU mode you may click the Jailbreak button. You need to continue holding the home button.
Step Seven
Greenpois0n will now jailbreak your device.
Click the Quit button once the software application has completed. Now you can release the Home button.
You’ll notice some text scrolling on your device.
Step Eight
After the iPhone restarts you’ll see a new Loader application on your Springboard. Press to launch it.
Step Nine
Select Cydia then press the large Install Cydia button that appears. Now Cydia will be downloaded from internet, so you need internet connection through wi-fi or edge/3g.
Step Ten
Once Cydia has installed successfully you can remove Loader by pressing the Options button then the large red Remove Loader.app button.
Step Eleven
Restart your iPhone and run Cydia. Let it do all the necessary updates.
You’re done!
Update:To change the boot logo back to Apple: install “Apple Boot Logo” from Cydia, then go to Settings-BootLogo and select Apple Logo.
These are step-by-step instructions on how to jailbreak iOS 4.2.1 on iPhone 3GS, iPhone 4, iPad, iPod Touch 2G, iPod Touch 3G, iPod Touch 4G using Greenpois0n for Mac OS X. Tutorial for Windows users is available here. All the steps are the same for all devices, we will cover iPhone.
Greenpois0n has been updated to support the iOS 4.1 and iOS 4.2.1 firmware. Use Limera1n if you want to jailbreak iOS 4.0, iOS 4.0.1, iOS 4.0.2.
Remember: Greenpois0n recommends a clean restore before continuing.
Unlockers: do not update to iOS 4.1 or iOS 4.2.1 if you need the unlock. Ultrasn0w does not support that baseband yet. The only exception is the iPhone 4. Experienced users can also try update to iOS 4.2.1 without upgrading your baseband by using TinyUmbrella. Start TSS Server->Start iTunes->Plug in your iPhone->Restore 4.2.1->Error 1013->Put phone into DFU Mode->Launch Greenpois0n.
We are not authors of this app. We do not promise that everything will go well, use this tutorial at your own risk.
Step One
Open your web browser and download the latest Mac version of GreenPois0n from here.
Step Two
When prompted save the download to your desktop.
Step Three
Double click the downloaded greenpois0n-osx_rc5.zip file to extract the archive. Then double click greenpois0n icon from the desktop to launch the application.
Step Four
Connect your iPhone to the computer, power it off. Then click the large Jailbreak button in greenpois0n app.
Step Five
You will now be instructed on how to place your iPhone into DFU mode. You will be asked to press and hold the sleep button (power button) for 3 seconds.
Now continue holding sleep button and and press home for 10 seconds.
Release sleep button and continue holding the home button. Do not release the Home button at this point!.
Step Six
Once your iPhone is successfully in DFU mode the jailbreak will begin. You need to continue holding the home button.
Step Seven
Now once Greenpois0n informs you that it has completed the jailbreak you can release the Home button.
Click the Complete button to close the application.
You’ll notice some text scrolling on your device.
Step Eight
After the iPhone restarts you’ll see a new Loader application on your Springboard. Press to launch it.
Step Nine
Select Cydia then press the large Install Cydia button that appears. Now Cydia will be downloaded from internet, so you need internet connection through wi-fi or edge/3g.
Step Ten
Once Cydia has installed successfully you can remove Loader by pressing the Options button then the large red Remove Loader.app button.
Step Eleven
Restart your iPhone and run Cydia. Let it do all the necessary updates.
You’re done!
Update:To change the boot logo back to Apple: install “Apple Boot Logo” from Cydia, then go to Settings-BootLogo and select Apple Logo.
The Chronic Dev-Team has finally released the new version of Greenpois0n, which features a full untethered jailbreak for iOS 4.2.1. No SHSH blobs needed. The exploit used has already been patched in iOS 4.3, so it not work on future iOS 4.3.
You can jailbreak iPhone 4, iPhone 3GS, iPod Touch 2G, iPod Touch 3G, iPod Touch 4G, iPad and Apple TV 2G. Unlike redsn0w 0.9.6 this is untethered, so there is no need to connect iOS device to a computer after restart.
There is only Mac OS X version available. Chronic Dev-Team will release Windows and probably Linux version soon.
Unlockers: do not update to stock iOS 4.2.1. You should keep your baseband version. Wait for new version of PwnageTool.