Determine Android N preview stage build I have Nexus 6P and I'm on Android Beta Program for Android N Developer Preview. From its program overview, it's stated that there will be 6 stages:


Preview 1 (initial release, alpha)
Preview 2 (incremental update, beta)
Preview 3 (incremental update, beta)
Preview 4 (final APIs and official SDK, Play publishing)
Preview 5 (near-final system images for final testing)
Final release to AOSP and ecosystem


How do I know which Android N preview stage I have?
Android provides release notes for Android N Developer Preview on here (as of current writing):


Developer Preview 1
Date: March 2016
Builds: NPC56P, NPC56R, updated: NPC56W, NPC56X
Developer Preview 2
Date: April 2016
Builds: NPC91K, NPC91O
Developer Preview 3
Date: May 2016
Builds: NPD35K
Developer Preview 4
Date: June 2016
Builds: NPD56N
Developer Preview 5
Date: July 2016
Builds: NPD90G


You can compare your build number with the available release notes by going to Settings - About phone - Build number.