If we talk about awesome Android devices, there's no doubt that the Samsung Galaxy S3 GT-I9300 is on that list. The phone's specs are precisely one of the reasons why developer support for this Samsung masterpiece is overwhelming, letting users enjoy the latest available customizations through new custom ROMs and mods. Joining the long list of new ROMs for this phone is AnonoROM.

Developed by XDA Developers member IOIDroid, AnonoROM is based on Android 4.1.2 Jelly Bean and is described as fast, smooth, and reliable. Aside from that, the ROM is also battery friendly, allowing you to do more with your phone's precious battery power. Included in the ROM are numerous handy modifications and tweaks for you to use. Whether you're a flashaholic or not, the AnonoROM is a must-try ROM.

This guide shows you how to flash AnonoROM 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 S3GT-I9300 with ClockworkMod Recovery installed.
  • You can check out our guide on how to root the Galaxy S3 and install ClockworkMod Recovery.
• Download the AnonoROM v20 (AnonoROMv20_1.zip, 405 MB).
• Make sure your phone'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 AnonoROM ZIP file to your phone's internal SD card.
2. Turn off your phone.
3. Boot it to Recovery Mode by holding down the Volume Up, Home, and Power buttons together until you see the Samsung Galaxy S3 logo on the screen.
   • Note: 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. Select Wipe Cache Partition > Yes.
6. Select Wipe Data/Factory Reset > Yes.
7. Select Mounts and Storage > Format /System > Yes.
8. Select Advanced > Wipe Dalvik Cache > Yes.
9. Select Install ZIP from SD Card > Choose ZIP from SD Card > select the AnonoROM file > Yes.
10. Once the installation is done, select Go Back > Reboot System Now.

Hooray! You just flashed the AnonoROM to the Samsung Galaxy S3 GT-I9300. Enjoy!