Just because Jelly Bean has been arriving on Android devices through both official and unofficial means doesn't mean you need to settle for the stock Jelly Bean experience. The beauty of Android is that Android developers can reinvent ROMs in their own ways, giving you things like phone-tablet hybrid UIs and imbuing your phone with the UI from a completely different phone. If you're itching to give your phone a revolution, you might want to take a look at the Android Revolution HD 12.0 ROM, developed by XDA Developers member mike1986.

Android Revolution HD for the Galaxy S3 I9300 has been hailed by users as “perfectly fast, smooth and stable.” It's based on Android 4.1.1 Jelly Bean and the official Samsung firmware I9300XXDLJ1. It includes the stock kernel, but if you want to try something different, you can also pick the Perseus custom kernel in AROMA Installer.

Android Revolution HD 12.0 also has root, that means SU and SuperSU permissions, and the latest BusyBox installed. The ROM has been stripped of its bloatware and it's been given speed optimizations. There's a whole lot more to this ROM so if you want a full list of its features, you'll have to check out the original development thread on XDA.

This guide shows you how to upgrade the Galaxy S3 I9300 to Android 4.1.1 Jelly Bean via Android Revolution HD ROM.

Warning

• The instructions in this guide are intended for use with the Samsung Galaxy S3, model number GT-I9300. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• Samsung Galaxy S3, model number GT-I9300, with ClockworkMod Recovery installed
  • For help with custom recovery, check our guide on how to flash ClockworkMod Touch Recovery 6.0.1.2 for the Galaxy S3 I9300
• Download the following files to your computer:
  • Android Revolution HD 13.0 ROM package (Android_Revolution_HD-SGS3_12.0.zip, md5sum: D6A2F040E38E50A30ABEBE0BC043ECBB)
  • Super Wipe Script (Android_Revolution_HD_Super_Wipe_Galaxy_S3.zip, 150 kB)
• Make sure your device's battery still has at least 70% power. You don't want the device to shut down in the middle of the procedure.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.

Instructions

1. Copy the Android Revolution HD ROM file and the Super Wipe Script to your Galaxy S3′s internal SD card.
2. Turn off your Galaxy S3.
3. Boot into Recovery Mode by pressing and holding down the Volume Up, Home, and Power buttons.
4. Make a NANDroid Backup by selecting Backup and Restore. Select Backup.
5. Select Install ZIP from SD card.  Select Choose ZIP from SD card and select the Super Wipe Script.  Confirm that you want to flash the package.  This step will fully wipe your phone in preparation for ROM flashing.
6. Select Chooze ZIP from SD card again and select the Android Revolution ROM package.  Confirm that you want to install it.  You will be able to configure installation options in the AROMA Installer, which will also provide you the choice to reboot your phone after installation.
7. If the phone doesn't reboot after flashing and returns to ClockworkMod Recovery, select Reboot System Now from the recovery menu.

Great job! Your Samsung Galaxy S3 GT-I9300 is now powered by Android Revolution HD and Android 4.1.1 Jelly Bean.