API Authorization OAuth 2.0(experimental) Login(experimental) Web Server(experimental) Client-side(experimental) Installed Apps(experimental) Devices(experimental) Older Protocols OAuth 1.0 for Web Apps OAuth 1.0 for Installed Apps OAuth 1.0 Reference AuthSub ClientLogin Using OAuth 2.0 for Login (Experimental) Google APIs use OAuth 2.0 for authentication and authorization. You can also choose to