Android 4.3 Jelly Bean updates for Galaxy Note II and Galaxy S4 have already been leaked and now it is the turns out that a test build of Android 4.3 Jelly Bean for the international version of Galaxy S III aka GT-I9300 has also been leaked.
Leaked by SamMobile the I9300XXUGMJ9 is a test build, but a stable one and includes a complete revamp of the user interface making it more like the one you would see in Galaxy Note 3 and Galaxy S4. However, you wouldn’t find Samsung Knox in this build and the launched is still the same. SamMobile notes that this is a test build and more features and UI changes are expected in the final version.
You can head on to SamMobile and download the firmware to try it out, but we would remind our readers that this is not an official release from Samsung if you proceed with flashing it on your Galaxy S III, the warranty will be void. Further, as the firmware will wipe you device, we recommend you backup before proceeding.