There are so many controversial opinions about jailbreaking that it is actually quite hard to make this decision. First of all you should know the basic difference between untethered and tethered jailbreak: an untethered jailbreak means you can turn off your device and reboot without the use of a computer, while a tethered jailbreak means you cannot reboot your device if you turn it off without the use of a computer.
So let’s move on how to actually apply an untethered jailbreak on your iPhone 4S running on updated iOS - 5.1. Before we actually get started, note that you proceed on your own risk and we are not responsible if you lose any data. So the first thing to do is to download the iPhone 4S jailbreak tool - Absinthe - from here. Note that Windows version is coming soon. Once the file is downloaded, follow the steps below carefully:
First thing to do is to open the file and plug your device in. if a passcode is enabled on your device, you should disable it right now.
Then check the “Jailbreak” button on the downloaded file and wait for the progress bar to be fully loaded. Don’t mess with your device!
Now you should see an Absinthe app installed on your iPhone 4S. Try opening the app and if you get a database error, keep closing and re-opening it till the app is opened properly.
When the app is completely loaded your iPhone should restart automatically. Once your device boots up, it will be successfully jailbroken!
Now you can make the best use of your updated iPhone 4S!