The Samsung Galaxy S3 GT-I9300 is currently one of the best devices on the Android market. Even then, there is still a way to make this device perform even better. With just your stock ROM, you are limited to the stock experience and features, but you could get so much more by stepping over to the dark side and by flashing custom ROMs. If you love the stock feel but not the limited stock experience, try installing the Dragon's Jelly Bean ROM on your phone for a sneak peek of what custom ROMs can do.

Developed by XDA Developers member Dragon7780, Dragon's Jelly Bean ROM is fast, stable, and packed with a lot of handy and functional modifications. This ROM will certainly reinvent how you experience Jelly Bean on your phone without heavily modifying the look of Samsung's stock software. The ROM is based on Android 4.1.1 build XXDLJ1. It has been deodexed, zipaligned, BusyBoxed, and comes with a lot of other goodies. The developer has tweaked ext4, SQLite 3, battery performance, and more so you can optimize your Galaxy S3.

This guide show you how to flash Dragon's Jelly Bean ROM for the Galaxy S3 I9300.

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

• A rooted Samsung Galaxy S3 model number GT-I9300.
  • For help, check out our guide on how to root and install ClockworkMod Recovery on your Galaxy S3.
• Download Dragon’s Jelly Bean ROM V4.0 (Dragons_JellyBean_V4.0.zip, md5sum: F7908F292CBABD50E9ABE258C2FF63CC) to your computer.
• 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 Dragon's Jelly Bean ROM to your phone's internal SD card.
2. Turn off your phone.
3. Boot it into Recovery Mode by holding down the Volume Up, Home, and Power buttons together until you see the Samsung Galaxy S3 text on the screen.
   • In Recovery Mode, use the Volume Buttons to navigate and the Power button to select options.
4. Do a NANDroid Backup of your current ROM. Select Backup and Restore > Backup.
5. Do a full wipe:
   • Select Wipe Data/Factory Reset > Yes.
   • Select Wipe Cache Partition > Yes.
   • Select Advanced > Wipe Dalvik Cache > Yes.
6. Select Install ZIP from SD Card > Choose ZIP from SD Card and select the Dragon's Jelly Bean ROM.
7. Once the installation is done, go back to the main menu and select Reboot System Now to reboot your phone.
8. Set up your account, let your phone settle for about 15 minutes, and then reboot it.

Congratulations! You have successfully flashed the Dragon's Jelly Bean ROM to the Samsung Galaxy S3 GT-I9300.