How ToROMs

Update Galaxy S3 I9300 to Android 5.1.1 Lollipop with Euphoria OS ROM [How to]

Samsung’s old flagship handset Galaxy S3 I9300 may no longer receive Android OS update support from its manufacturer. But these devices can be updated now to the Euphoria OS custom ROM which is based on the AOSP (Android Open Source Project) and Galaxy S3 (international variant) users can easily flash this custom ROM based on Android 5.1.1 Lollipop which is popular for customizations and plenty of tweaks in the Android ROM market. Get ready to experience the latest Android OS version on your Galaxy S3 I9300? Go ahead and follow the given detailed guide.

Before going ahead, please note that this is an unofficial build of the Euphoria OS with the latest Lollipop version 5.1.1. You might face some not functioning features and bugs are highly likely but the developers are working hard to fix them in the next update.

Update Galaxy S3 I9300 to Android 5.1.1 Lollipop

Check out the changelog of Android 5.1.1. Euphoria OS ROM:


  • Merged android-5.1.1_r3 – android-5.1.1_r4
  • Merged in translations from CM
  • Show multi-line notification if there’s more than one missed call
  • DeskCLock – Expose background colors for theming
  • Settings: add Bluetooth tethering option to BT overflow menu
  • Settings: update dashboard icons
  • Simple option to use volume keys to control media volume anytime (removed old options)
  • Use WindowManager to set custom DPI (fixes broken legacy apps)
  • Double tap to sleep anywhere on the lock screen
  • Option to disable torch when the screen turns off
  • QS panel Task Manager
  • Fix setting up linked notification stream on boot
  • Fix adding headsup view after boot
  • Prompt for SIM PIN if lockscreen is disabled

Device specific changes

  • 20150607- New sensor stuff, some optimisations
  • 20150505- GPS Fixed again since last build broke it
  • 20150425- GPS FIXED
  • 20150403-SE Linux fixed, now on enforcing, GPS fixed


The Euphoria OS ROM and instructions given in this guide are working only with Galaxy S3 model no I9300. Check the model number of your device, if it is I9300 then go ahead, otherwise not. Do not try to install this firmware on any other device or incorrect variant.


AndroidBlog will not be held responsible for any kind of damage occurred to your Galaxy S3 I9300 during or after the installation of Euphoria OS ROM. Proceed at your own risk.


  • Make a proper backup of all your important data and settings using a custom recovery such as CWM or TWRP.
  • Enable USB Debugging on the Galaxy S3 by navigating to Settings > Developer Options.
  • The battery level of your S3 should be at least about 80% to prevent unexpected shutdowns while flashing the Euphoria OS custom ROM.
  • Your device should be rooted and the latest version of a custom recovery must be installed on it.

Required Files:

Steps to Update Galaxy S3 I9300 to Android 5.1.1 Lollipop with Euphoria OS ROM:

Follow the given instructions to install Android 5.1.1 Lollipop on Galaxy S3 via Euphoria OS ROM:

1:- First, download Android 5.1.1 Euphoria OS ROM ( for your Galaxy S3 on the desktop of your PC.

2:- Connect the Galaxy S3 with PC using a USB data cable and copy the downloaded ROM file to the root folder of internal storage of the phone.

3:- Turn OFF the Galaxy S3 to boot into Recovery Mode.

4:- Turn ON while pressing the Power + Home + Volume Up keys at the same time.

6:- While your device is now in CWM Recovery, perform wipe data/factory reset, wipe cache partition and wipe dalvik cache also by navigating to Advanced > Wipe Dalvik Cache.

Note:- wipe dalvik cache will help you to prevent boot loops and other errors while ROM installation.

7:- Go back to the main Recovery Menu and choose install zip from SD card → choose zip from sdcard.

8:- Navigate to the Euphoria OS custom ROM .zip file which you’ve already transferred to the SD card of your device previously. Select the ROM .zip file using the Power button and confirm the installation to begin.

9:- Next, install Google Apps by repeating the above steps.

10:- Navigate to +++++Go Back+++++ once the installation is completed. From Recovery Menu, reboot your device by selecting reboot system now.

Your Galaxy S3 will be rebooted and may take about 4 to 5 minutes to boot for the first time after installation.

Done! You’ve successfully updated Galaxy S3 I9300 to Euphoria OS ROM featuring Android Lollipop v5.1.1.


If your Galaxy S3 experience boot loop or gets stuck on booting animation after flashing the ROM then perform wipe cache partition and wipe dalvik cache for a few times before rebooting the Galaxy S3.

Let us know in the comments area below if you have any query or trouble while installing this custom ROM on your Galaxy S3.

Aamir Jamal

An Android Geek and audiophile who love to read and write reviews/tutorials about gadgets and new tech stuff. He has written 1007 guides and other posts.

Related Articles

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button