http://wccftech.com/update-galaxy-s3-to-android-8-oreo-custom-rom/ >Wondering if you could, just maybe, try out Oreo on your Samsung Galaxy S3? Lineage OS custom firmware is now available for the device, but is highly unstable. Based on Android 8.0.0 Oreo, the ROM is an early built that is designed for developers who want to help build it and for early testers. If you have the device lying around for testing purposes, here is how to update Galaxy S3 to Android 8 Oreo. >Note: this tutorial is focused on Samsung Galaxy S3; please do not try this guide on other Android or Samsung devices. Also, as mentioned before, this is NOT for your daily driver, so install it only if you are into testing early releases of custom ROMs.