Samsung Galaxy S3 (LTE) I9305/T/N users who have already updated their devices with Android 4.1.2 Jelly Bean, may root their devices using the tutorial below.
This tutorial uses CF-Auto-Root file released by recognised XDA Developers, Chainfire. The CF-Auto-Root file allowing Galaxy S3 users to root their devices easily without depending on the firmware. It completely supports Android 4.1.2 Jelly Bean and future firmware as well. Head over to the CF-Auto-Root main thread to learn more about the root method.
Disclaimer: Rooting voids the warranty of your device. We and the developer of this rooting procedures shall not be held responsible if any undesirable outcomes may happen to your device. use of this root guide is solely at your own risk!
1) Install USB Driver for Samsung Galaxy S3 on the computer.
2) Enable USB Debugging Mode on the phone by navigating to Settings >> Developer Options (Android 4.0 or later) or go to Settings >> Applications >> Development (Android 2.3 or earlier).
3) Make a backup of all your important data before following the guide.
4) Ensure the battery of the phone is charged more than 80 per cent.
5) The CF-Auto-Root file works only on Samsung Galaxy S3 (LTE) I9305/T/N. Applying this to any incorrect variant might brick the device. Verify the model number of the Galaxy S3 by navigating to Settings >> About Phone.
1. CF-Auto-Root for Galaxy S3 (LTE) GT-I9305 (CF-Auto-Root-m3-m3zh-gti9305.zip), GT-I9305T (CF-Auto-Root-m3-m3dv-gti9305t.zip), or GT-I9305N (CF-Auto-Root-m3-m3swexx-gti9305n.zip)
2. Odin 3.07 (Mirror Link)
Steps to Root Galaxy S3 (LTE) I9305/T/N Running on Android 4.1.2 Jelly Bean Firmware
Step 1: Extract CF-Auto-Root and Odin 3.07 files using WinRAR/7-Zip/WinZip or any other extracting tool.
Step 2: Switch off the Galaxy S3. Then boot the device into Download Mode by pressing and holding Volume Down + Home buttons together and then press the Power button until the device turns on. Now press the Volume Up button to enter Download Mode.
Step 3: Launch Odin on the computer.
Step 4: Connect the Galaxy S3 to the computer using USB cable while it is in the Download Mode. Wait until Odin detects the device. When the device is connected successfully, the ID: COM box will turn yellow with the COM port number. Additionally, the successful connected will be indicated by a message saying Added. If Odin fails to detect the device then re-install USB driver
Step 5: In Odin, click the PDA button and select the CF-Auto-Root with a .tar.md5 file.
Step 6: Verify that Auto Reboot and F.Reset Time checkboxes are selected in Odin. Also, ensure the Re-Partition option in Odin is NOT selected.
Step 7: Double-check and click Start in Odin. The installation process will now begin.
Step 8: Once flashing completed, your phone will restart and soon you will see a PASS message with green background in the left-most box at the very top of the Odin. You can now unplug the USB cable to disconnect your device from computer.
Samsung Galaxy S3 (LTE) I9305/T/N running on Android 4.1.2 Jelly Bean firmware is now rooted successfully. You can now install any app that requires root permission. Verify the root status of the device by downloading Root Checker app from Google Play Store.
Thank's to all fellas at XDA who first tried out this rooting technique. This method was originally posted via XDA-Developers original thread.