What is 2FAS Auth used for?

2FAS Auth is the open-source Android app for generating two-factor authentication codes using TOTP and HOTP standards. It is a good fit for adding second-factor codes to online accounts and replacing SMS-based verification.

Is 2FAS Auth open source?

Yes. 2FAS Auth is open source under the GPL-3.0 licence. Its source code is on GitHub at twofas/2fas-android and is written mainly in Kotlin.

Yes. 2FAS Auth is open source, so the software itself is free to use.

Can I self-host 2FAS Auth?

Yes. 2FAS Auth can be self-hosted on your own server or infrastructure.

What is 2FAS Auth an alternative to?

2FAS Auth is an open-source alternative to Microsoft Authenticator and Google Authenticator. Other open-source alternatives to Microsoft Authenticator include Aegis Authenticator and 2FAuth.

Is 2FAS Auth actively maintained?

Yes. The most recent commit to 2FAS Auth was on 29 September 2026, and the latest release is 6.0.3, published on 29 September 2026. The project has 1.5k stars on GitHub.

2FAS Auth: open-source auth & identity

About 2FAS Auth

This repository holds the official Android app for the Open Source 2FAS project, a two-factor authentication service. Two-factor authentication adds a second step to sign-in, such as a one-time password shown on your phone, so that a stolen password alone is not enough to access an account. The app is written in Kotlin and licensed under GPL-3.0.

The app supports time-based one-time passwords and HMAC-based one-time passwords, which means it works with any service that follows those standards, including Google, Microsoft and Dropbox. The README describes it as easy to set up and use. Installation is from the releases page, followed by on-screen instructions to add your online accounts.

The project handles bug reports through GitHub issues and asks for security reports to go to a dedicated email address instead. Contributions are welcome through a contribution guide, and donations support ongoing development. The README notes that the app's graphics are not part of the open-source project and carry their own licensing terms.

Key features

Time-based one-time passwords (TOTP)
HMAC-based one-time passwords (HOTP)
Works with any standard-compliant service
Releases published on GitHub
Separate channel for security reports

Good fit for

→Adding second-factor codes to online accounts
→Replacing SMS-based verification

Built with: Kotlin
Tags: 2fa; totp; hotp; authenticator; android; security; kotlin; two-factor

2FAS Auth: questions and answers

What is 2FAS Auth used for?: 2FAS Auth is the open-source Android app for generating two-factor authentication codes using TOTP and HOTP standards. It is a good fit for adding second-factor codes to online accounts and replacing SMS-based verification.
Is 2FAS Auth open source?: Yes. 2FAS Auth is open source under the GPL-3.0 licence. Its source code is on GitHub at twofas/2fas-android and is written mainly in Kotlin.
Is 2FAS Auth free?: Yes. 2FAS Auth is open source, so the software itself is free to use.
Can I self-host 2FAS Auth?: Yes. 2FAS Auth can be self-hosted on your own server or infrastructure.
What is 2FAS Auth an alternative to?: 2FAS Auth is an open-source alternative to Microsoft Authenticator and Google Authenticator. Other open-source alternatives to Microsoft Authenticator include Aegis Authenticator and 2FAuth.
Is 2FAS Auth actively maintained?: Yes. The most recent commit to 2FAS Auth was on 29 September 2026, and the latest release is 6.0.3, published on 29 September 2026. The project has 1.5k stars on GitHub.