Alternatives to 2FAS

Open-source authenticator app with browser-extension push approvals. The listings below can replace it for an important use case. Each note says what changes if you switch.

Replacements

Listings that take over the same core job as 2FAS.

  • Ente Auth

    Open-source two-factor authenticator with end-to-end encrypted backups.

    FreeOpen sourceWindowsmacOSLinuxAndroidiOSWeb

    Ente Auth adds desktop and web clients with free end-to-end encrypted cloud backup under AGPL-3.0, but backup relies on an Ente account instead of your own drive.

  • Aegis Authenticator

    An encrypted two-factor authentication app for Android with real backups and imports from every other authenticator.

    FreeOpen sourceAndroid

    Aegis keeps codes in an encrypted vault with automatic backups to a location you choose and broad imports, but it runs only on Android and has no browser extension.

  • Google Authenticator

    Google's mobile app that generates one-time verification codes for two-step verification.

    FreeProprietaryAndroidiOS

    Google Authenticator syncs codes through a Google Account instead of your own cloud drive, is closed source and has no browser extension for push approvals.

  • Authy

    Mobile two-factor authenticator with encrypted cloud backup.

    FreeProprietaryAndroidiOS

    Authy offers encrypted backup and multi-device sync on Android and iOS, but it is closed source and account recovery is tied to a phone number.

  • Proton Authenticator

    A free two-factor authentication app from Proton with end-to-end encrypted sync between your devices and no advertising.

    FreeOpen sourceWindowsLinuxAndroid

    Proton Authenticator adds desktop apps with end-to-end encrypted sync under the GPL, but sync requires a Proton account and there is no browser extension.

  • FreeOTP

    An open-source two-factor authentication app for Android and iOS that generates one-time codes.

    FreeOpen sourceAndroidiOS

    FreeOTP is a free open-source mobile app available on F-Droid as well as Google Play and the App Store, with minimal documentation and no browser extension.

  • Microsoft Authenticator

    Microsoft's mobile authenticator app for multi-factor and passwordless sign-in to personal and work accounts.

    FreeProprietaryAndroidiOS

    Microsoft Authenticator adds passwordless sign-in for Microsoft personal and work accounts, but it is closed source, mobile only and most useful inside the Microsoft ecosystem.

  • Bitwarden Authenticator

    A standalone mobile app from Bitwarden that generates and stores two-step verification codes.

    FreeProprietaryAndroidiOS

    Bitwarden Authenticator is a free standalone mobile app from a password manager vendor, but it is not open source and few import or backup details are published.

Also worth comparing

These listings name 2FAS as their own alternative, so the relationship runs both ways.

  • Authenticator

    A GNOME desktop app that generates two-factor authentication codes using the TOTP and HOTP standards.

    FreeOpen sourceLinux

    2FAS moves codes to an Android or iOS phone, stays open source, and adds browser-extension push approvals and encrypted backups to iCloud or Google Drive.

  • Duo Mobile

    Enterprise multi-factor authentication app with push approvals.

    FreeProprietaryAndroidiOS

    2FAS is open source and free, with push approvals through a browser extension instead of an organisation's paid Duo deployment.

  • OTPClient

    A GTK4 desktop app for managing TOTP and HOTP two-factor codes in encrypted databases.

    FreeOpen sourceLinuxCommand line

    2FAS moves codes to Android or iOS with browser-extension push approvals and encrypted backups to iCloud or Google Drive, but has no standalone desktop app.

  • Step Two

    A two-step verification code app for iPhone, iPad, Apple Watch and Mac with iCloud backup.

    PaidProprietarymacOSiOSBrowser extension

    2FAS is free and open source on iOS and Android, keeps iCloud backup, and adds browser-extension push approvals, but has no Mac app or Apple Watch app.

  • Stratum

    A free and open-source two-factor authentication app for Android with encrypted backups and Wear OS support.

    FreeOpen sourceAndroid

    2FAS is open source on Android and iOS, adds browser-extension push approvals, and backs up to your own Google Drive or iCloud account.

  • Yubico Authenticator

    An app that shows two-factor codes from OATH credentials stored on a YubiKey.

    FreeProprietaryWindowsmacOSLinuxAndroidiOS

    2FAS is an open-source Android and iOS app with browser-extension push approvals and encrypted cloud backups, storing secrets on the phone rather than a YubiKey.

Similar software

Related functionality, not a direct replacement.