The Android O is upcoming operating system version for mobile devices. Under the Android Open Source Project (AOSP), Google’s software development team deploys a new Android version each year and security patch updates every month. Not long ago Google decided to release a Developer Preview first, termed as Beta update, and then the official one. This is the last but one Developer Preview update with v3. The Android O Beta program will still carry on until the official AOSP sources are updated in August 2017. This preview 3 updates the last of its APIs. Download the final API 26 SDK from the SDK Manager found in Android Studio.
Devices which will receive the official Android O update are Nexus 5X, Nexus 6P, Google Pixel (XL), Pixel C, Nexus Player. Unfortunately, the Nexus 6, 5, 4 are officially out of support period. Before you hop into flashing the factory images of the new preview version, you need to know that this is meant for developmental purposes only. As the update is not stable, you may expect some bug and instability issues. Not much is known about the update at this moment.
Download Android O Developer Preview 3
The listed files are the full factory images fro Nexus and Google pixel devices. There is a simple way to flash them. Simply download the factory images, extract the zip files and run the “Flash-all.bat” file on your PC. But first, make sure ADB and Fastboot are setup on you Windows, Mac, or Linux machine. Check out the full tutorial on how to flash factory images on Nexus and Google devices.