CM12.1 ROM for Galaxy S3! [Android 5.1]

Want to experience Android 5.1 on your Galaxy S3 today?  Even newer smartphones like Galaxy S6 and HTC One M9 don’t have Android 5.1 yet but you can already get it for your Galaxy S3 through CM12.1 ROM.

The CM12.1 ROM builds are available for all AT&T, T-Mobile, Sprint, Verizon, Canadian, and GT-i9300 Galaxy S3 models.  Although these are unofficial builds compiled from CyanogenMod sources, they are actually pretty stable, I haven’t found a single bug yet so far.

Since the update from Android 5.0.2 to 5.1 wasn’t a complete overhaul of the OS, we suspect that has a lot to do with its stability as developers don’t have to start from scratch to make everything integrated/stable.

Overall, Android 5.1 is going to give you the most performance improvement over previous Android OS versions along with much improved battery life.  If you can’t afford a new phone but you want to upgrade your phone for free, CM12.1 ROM may be the best way to do that so definitely give these builds a try and do let me know what you think!


(These unofficial builds are compiled from official Cyanogen sources, no bug found so far.)


You will find easy drop-down WiFi and bluetooth shortcuts, which is a new feature of Android 5.1.


With Android 5.1 CM12.1 ROM, you can specify exactly which apps can notify you and also set the priority for these notifications.


Have more than one user?  Take advantage of Android 5.1 Lollipop multi-user feature.


Camera and camcorder work flawless and CM12.1 comes with rotating launcher.


Download CM12.1 ROM for Galaxy S3 AT&T SGH-i747, T-Mobile SGH-T999, and Canadian SGH-i747M

Download CM12.1 ROM for Galaxy S3 Sprint SPH-L710

Download CM12.1 ROM for Galaxy S3 Verizon SCH-i535

Download CM12.1 ROM for Galaxy S3 GT-i9300

Download Android 5.1 Gapps for CM12.1 (DO NOT USE older Gapps, you will FC!!!)

To install, reboot into recovery, make backup ROM, format /system, wipe data/factory reset, install ROM, install Gapps, and reboot.

If you have AT&T or Verizon S3 with locked bootloader (Android 4.3 or up) and using SafeStrap, YOU CANNOT INSTALL THIS ROM, SORRY!

First time installing a custom ROM? See How to Install Custom ROM on Galaxy S3!

Can’t find root?  See How to Enable Root on CM12!

Credits – AT&T/T-Mobile/Canadian, Sprint, Verizon, GT-i9300 <— Please donate to the developers or hit the Thanks button on XDA if you like this ROM,thx!

Extra Mods

Have a question?

This is an OLD website where we no longer support and we are moving all our new tutorials to our new forum where you can ask questions about any Android device. Please post all your questions at the new Android Rehab Center at HighOnAndroid Forum, thank you for understanding!

You may also like...