Android developers can now access the Android 8.1 Oreo API today, and Google will be rolling out the next version of Android to compatible Pixel and Nexus devices over the next week.
Owners of the 2016 Pixel twins, the Pixel C, as well as the Nexus 5X and 6P can expect the update first.
If you don’t want to wait for the update notification, you can sign up for the Android Beta program to quickly receive the full version of Android 8.1.
You can also unlock your bootloader and flash the stock Nexus or Pixel image — which is a bit of a complicated process — or you can sideload the OTA update file. However, sideloading the OTA update is yet another lengthy process.
It should also be mentioned that the Pixel 2 XL at the MobileSyrup offices has yet to receive the Android 8.1 update notification. Still, we’ll remain vigiliant knowing that it should be arriving soon.
Source: Android Developers Blog