At Google I/O developer conference, Google has unveiled Android O Beta program for Nexus and Pixel devices. Users of the supported phones can test the next release of Operating System before it is finalized and launched officially.
Android O Developer Preview was out in March but Google has warned the non-developers not to run it because it was an early release and bugs were expected everywhere. But this is Beta program and would be a little better than the Developer Preview. You can enroll your device on Google’s website if you want to test the Beta version of Android O. You can enroll only these phones for testing the Beta version- Google Pixel, Pixel XL, Pixel C, LG Nexus 5X, Huawei Nexus 6P and Asus Nexus Player.
Three Beta builds will be coming over the next few months. According to the announcement Google developed it in March, first one will arrive now as OTA software update on enrolled devices. The second one will be coming in mid to late June and the third and last Beta will arrive in mid to late July. Hence, the users can expect the final version of Android O before the end of August.