With a device as popular as the Samsung Galaxy S III, achieving root on all variants is high priority. Now, all three U.S. carrierversions, the Sprint, T-Mobile and AT&T Galaxy S III have been rooted.
With so many phones getting root all at once, there are quite a few XDA members responsible—XDA Senior Member howtomen for the AT&T version, XDA Forum Member cypher_zero for the Sprint and T-Mobile version, and XDA Forum Member dawgslayer69 for posting that the cypher_zero’s Sprint method is compatible with the T-Mobile variant. Cypher_zero’s method actually comes from XDA Recognized Developer noobnl‘s original root and recovery method for Sprint variant, just made a bit more digestible for new users.
The process is what has become the standard for rooting most Samsung devices. Users will be directed to use the latest version of Odin to flash a kernel and ClockworkMod Recovery onto the device, and then use ClockworkMod Recovery to flash root. The only difference is the files being used.
The AT&T method has it’s own files and is confirmed working. In a surprising twist, the Sprint and T-Mobile root methods are actually identical. Although there were initially some doubts, the method has been confirmed working. It may actually probably be possible to root the AT&T version with the Sprint / T-Mobile method as well, as it’s been reported that the kernel is universal between all three, but for now it’s safest to stick with the procedures that work.
Head over to the appropriate root thread to get started: