An Android 4.3 Jelly Bean build for the Samsung Galaxy S3 has leaked online and is now available for download, albeit it's unofficial.

The latest Jelly Bean firmware has recently made its way online for the Galaxy S4 and Galaxy Note 2, and now it seems to be the turn of last year's flagship Galaxy smartphone.

The new firmware for the Galaxy S3 comes courtesy of a SamMobile source. This is the very first Android 4.3 Jelly Bean leak for the Galaxy S3. It is quite stable, but it's still a test build, which means that this I9300XXUGMJ9 version may have a few bugs.

Android 4.3 brings several changes to the Samsung Galaxy S3, including a complete overhaul of the user interface (UI). According to SamMobile, the new UI is now similar to that of the Galaxy S4 and the Galaxy Note 3. The Settings tab now sports a new tabbed interface as well.

On the other hand, the new build still has the same original launcher and widgets. Moreover, this test version of Android 4.3 does not feature the Samsung Knox security suite, which is expected to be available with the final release of the firmware. The final build may also bring more features and UI changes.

The new Android 4.3 Jelly Bean firmware for the Samsung Galaxy S3 is available for download at this link or this one. For instructions on how to install it, check out SamMobile's guide.

The publication has tested this test build and claims that it is stable, but keep in mind that unofficial firmware always entails a risk. Those who decide to flash custom ROMs and unofficial, leaked firmware must be aware that they do so at their own risk. At least some sort of tech-savvy skills are recommended.

That said, if you still want to try out this Android 4.3 firmware for the Samsung Galaxy S3, make sure you follow the instructions exactly as listed. Remember to back up your data as well, including files stored on the internal SD card. If you go ahead with this build, let us know how it all works out.