Compare software

Google AuthenticatorProton Authenticator
Free

Free to download and use.

 Free

Free and open source under the GPL, with no advertising. A Proton account is used for…

Android, iOS Windows, Linux, Android, iOS
  • Generates codes without a network connection
  • Optional sync of codes across devices via a Google Account
  • End-to-end encrypted sync between devices, which most free authenticators lack
  • Apps for Android, iOS, Windows, Linux and macOS
  • Cloud sync ties your codes to a Google Account
  • Not open source
  • Sync requires a Proton account
  • Keeping codes on the same desktop you log in from weakens second-factor separation
Downloadable app Downloadable app
Closed source Open source
License not stated License: GPL-3.0
Not stated if an account is needed No account needed
Works offline Works offline

Checked September 23, 2026

Checked September 21, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.