Android Marshmallow on the Samsung Galaxy S3Samsung does not have any plans to bring Android Marshmallow to the Samsung Galaxy S3, which should come as no surprise, given that the device didn't receive Lollipop, either.
An unofficial Marshmallow ROM has appeared through the XDA Developers forum, but its stability is questionable and updates are uncertain. We would recommend using it with caution.
CyanogenMod has also committed to bringing CyanogenMod 13 updates, based on Android Marshmallow, to the i9300 model of the Samsung Galaxy S3. A timeframe for the update has not been given, but it can be expected to be sluggish and buggy from the outset. Prepare to wait quite a while before anything stable emerges.
Android Lollipop on the Samsung Galaxy S3While the Samsung Galaxy S3 remains stranded on Android KitKat across the board, an update for Sprint customers bearing a security path for the Stagefright exploit brings devices up to version L710TVPU0AOH1 and should have been received by all Galaxy S3 handsets now. If you haven't been prompted to update already, go to Settings > About Phone > Software update to download the patch.
Though AT&T issued a security update for the S3 on August 18, updates from the other major US networks are still to come. We don't have an ETA yet, but we will update this page when we learn more.
Samsung has officially ruled out the possibility of a Samsung Galaxy S3 Android Lollipop update via Twitter. It's no surprise, given that the Galaxy S3 is now three years old, but those of you who were expecting the Galaxy S3 update on Sprint, Verizon, AT&T or T-Mobile will be disappointed.
There is a custom version of Android Lollipop available for the Galaxy S3 (GT-I9300), however, which you can download now.
How to install Android Lollipop on the Galaxy S3Over at the XDA Developers forum, Android developers JustArchi and Moster2 have created a CyanogenMod 12.1 build based on Android 5.1.1 Lollipop for rooted Galaxy S3 (GT-I9300) owners.
It's a work in progress, but all of the major device features are up and running, including Lollipop additions such as the Material Design aesthetic and lock screen notifications. If you'd like to install it in its current state, check out the CyanogenMod Wiki entry for the GT-I9300.
We'll let you know about any other Galaxy S3 Android Lollipop developments as we get them. For now, if you just want to pretend your S3 has Lollipop, find out how to get Android 5.0 Lollipop apps, UI and features on your phone without root.
Have you tried flashing a custom ROM on your Samsung Galaxy SIII? Let us know in the comments below.