Android 4.1 Jelly Bean was introduced in the recent Google I/O 2012 exhibition and soon afterwards the Jelly Bean update rolled out in the form of an OTA update for the Galaxy Nexus GT-I9250.

For those of you who don’t know it yet, Jelly Bean is the latest addition to the ever-growing versions of Android. Jelly Bean brings a lot of enticing new features to the table, such as faster performance, offline voice typing, refined Google Search functionality, and a whole lot more.

Thanks to XDA Developers member Faryaab,who managed to port the Android 4.1 Jelly Bean ROM to the Galaxy S3, owners of the Galaxy S3 GT-I9300 can now enjoy it first-hand on their phones. Since this is an unofficial port, some features may still not work and users might experience some bugs that need to be weeded out. As a reminder, you should use this ROM only to try out Jelly Bean and not as a replacement.

To get the latest Android, check our guide on how to update the Galaxy S3 I9300 to unofficial Android 4.1 Jelly Bean.

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

• Rooted Samsung Galaxy S3 with ClockworkMod Recovery.
  • Need help with rooting? You can refer to this guide how to root and flash ClockworkMod Recovery on your mobile phone.
• Download the ported Android 4.1 Jelly Bean ROM (Android-4.1-JellyBean-GNex-OTA-Port.zip, 217 MB).
• 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-4.1-JellyBean-GNex-OTA-Port.zip file and place it in your phone’s internal SD card.
2. Switch off your phone.
3. Boot into ClockworkMod Recovery. You can do this by pressing and holding down the Volume Up, Home, and Power buttons together until your phone screen turns on. Wait for a couple of seconds and it will boot into recovery. Use the Volume buttons to navigate and the Home button to select an option.
4. Make a NANDroid backup of your existing ROM. To create a backup, select Backup and Restore then select Backupagain on the next screen.
5. Select Wipe Data/Factory Reset, then select Yeson the next screen to confirm data wipe.
6. Select Wipe Cache Partition and confirm the action on the next screen.
7. Go back to the main menu and select Advance. From there, select Wipe Dalvik Cache and confirm the action on the next screen.
8. Return to the main menu and select Install ZIP From SD Card.
9. Select Choose ZIP From SD Card then browse for Android-4.1-JellyBean-GNex-OTA-Port.zip file and select it. Confirm the installation by selecting Yeson the next screen that follows. It may take 5-10 minutes for the ROM to finish installing.
10. Head back to the main menu by selecting Go Back.
11. Reboot your phone by selecting Reboot System Now to finish the installation process.
    • Note: If you want to go back to your previous ROM, simply shut down your phone and boot back to Recovery Mode. SelectBackup and Restore and selectRestore to restore your backup ROM.

Congratulations! You have successfully installed Android 4.1 Jelly Bean on your Samsung Galaxy S3 GT-I9300.