Google Authenticator logo vector

Google Authenticator is a software-based authenticator by Google. It implements multi-factor authentication services using the time-based one-time password and HMAC-based one-time password, for authenticating users of software applications.

When logging into a site supporting Authenticator (including Google services) or using Authenticator-supporting third-party applications such as password managers or file hosting services, Authenticator generates a six- to eight-digit one-time password which users must enter in addition to their usual login details.

Google provides Android, BlackBerry, and iOS versions of Authenticator.

An official open-source fork of the Android app is available on GitHub. However, this fork has not been updated since 2020. Likewise, the source code is also freely available for old versions of the Google Authenticator apps for iOS and BlackBerry. This source code also has not been updated in years.

Current software releases are proprietary freeware.