What are Google Pay compatible Android devices?

Smartphone and Tablet
Any smartphones and tablets running Android Lollipop (5.0) or higher.
To use Google Pay™ for contactless in-stores payments, the Android device must:

support near-field communication (NFC)
support host card emulation (HCE).

Android tablets and any Android phones that do not support NFC can only be used for payments in apps or on websites.
For more details, go to Fix problems with tap-to-pay transactions - Google Wallet Help