# Open-source two-factor authentication

14 open-source two-factor authentication rated against public privacy criteria.

1. [Aegis](https://privacyratings.com/two-factor-authentication/aegis/): B (80/100). Free and open source authenticator app for Android that stores codes in an encrypted local vault. It supports encrypted backups, imports from many other authenticator apps and has no internet permission.
2. [Authenticator](https://privacyratings.com/two-factor-authentication/authenticator/): B (80/100). Open source two-factor authentication app for iOS that stores secrets encrypted in the iOS keychain. The app never connects to the internet.
3. [Authenticator CC](https://privacyratings.com/two-factor-authentication/authenticator-cc/): B (80/100). Open source browser extension for Chrome, Firefox and Edge that generates TOTP and HOTP codes. Accounts can be encrypted with a password and backed up to a file or the user's cloud storage.
4. [Authenticator GNOME](https://privacyratings.com/two-factor-authentication/authenticator-gnome/): B (80/100). Open source two-factor code generator for the GNOME desktop, written in Rust. It supports TOTP, HOTP and Steam codes, a GNOME Shell search provider and backups to and from other authenticator apps.
5. [Chronos Authenticator](https://privacyratings.com/two-factor-authentication/chronos-authenticator/): B (80/100). Open source two-factor authentication app for iOS that supports TOTP and HOTP codes. Tokens are encrypted on the device, with optional encrypted iCloud sync and exports.
6. [FreeOTP](https://privacyratings.com/two-factor-authentication/freeotp/): B (80/100). Open source two-factor authentication app sponsored by Red Hat that generates HOTP and TOTP codes. Tokens are added by scanning a QR code.
7. [FreeOTP+](https://privacyratings.com/two-factor-authentication/freeotp-plus/): B (80/100). Open source fork of FreeOTP for Android that adds backup export and import, search, categories, biometric lock and offline token icons. Generates HOTP and TOTP codes.
8. [Stratum](https://privacyratings.com/two-factor-authentication/stratum/): B (80/100). Free and open source two-factor authentication app for Android with encrypted backups, icon packs, categories and a Wear OS companion app. It imports from many other authenticator apps.
9. [Bitwarden Authenticator](https://privacyratings.com/two-factor-authentication/bitwarden-authenticator/): C (70/100). Free, open source authenticator app for iOS and Android from Bitwarden that generates TOTP codes. It works without an account and can optionally sync codes with a Bitwarden password manager vault.
10. [Ente Auth](https://privacyratings.com/two-factor-authentication/ente-auth/): C (70/100). Free, open source TOTP authenticator for mobile, desktop and web. Works fully offline, or with an Ente account to sync codes across devices with end-to-end encrypted backups.
11. [Proton Authenticator](https://privacyratings.com/two-factor-authentication/proton-authenticator/): C (65/100). Free, open source authenticator app from Proton for Android, iOS, macOS, Windows and Linux. It works without an account, and signing in with a Proton account adds end-to-end encrypted sync.
12. [2FAS](https://privacyratings.com/two-factor-authentication/2fas/): D (50/100). Open source authenticator app for Android and iOS with a browser extension for filling codes. Backups can be encrypted and synced through the user's Google Drive or iCloud without a 2FAS account.
13. [Tofu](https://privacyratings.com/two-factor-authentication/tofu/): D (50/100). Open source two-factor authentication app for iOS that generates TOTP and HOTP codes. It works without a network connection.
14. [Yubico Authenticator](https://privacyratings.com/two-factor-authentication/yubico-authenticator/): D (50/100). Authenticator app from Yubico that stores OATH one-time password secrets on a YubiKey instead of the phone or computer, and generates codes when the key is connected or tapped.

Source: https://privacyratings.com/open-source/two-factor-authentication/