Open Source Google Authenticator Alternatives

Aegis is an Android authenticator app built for people who want full control over their 2FA tokens without handing them off to a cloud service they don't own. No ads, no unnecessary permissions, no lock-in to a phone number or SIM card. It works entirely offline.

The vault is encrypted by default. You choose the password, and optional biometric unlock (fingerprint or face) makes day-to-day access quick without sacrificing security. The app requests only three permissions, a sharp contrast to many alternatives that ask for far more than they need.

Key capabilities:

• Encrypted vault with password protection and optional biometric unlock
• Flexible backups that you control, saved wherever you want, with automatic backup prompts and optional password encryption on the backup file itself
• Import and export from Google Authenticator, Authy, Microsoft Authenticator, andOTP, FreeOTP+, and others. On rooted devices, it can pull data directly from other installed authenticators
• Multiple TOTP algorithms beyond the SHA1 baseline that many apps limit you to
• Customizable interface with Material You support, true dark mode, tiles view, and icon packs to help you find tokens quickly

Migrating from another authenticator is straightforward. If you've ever been stuck on a phone upgrade because Google Authenticator wouldn't recognize its own QR code, Aegis handles that transition without friction.

Aegis has over 675,000 installs and is actively maintained.

2FAS is a privacy-focused authenticator and password manager built for people who want full control over their security data. Everything stays on your device by default. No account, no server, no data collection. That's the core premise.

The authenticator handles TOTP-based two-factor authentication tokens. You can organize tokens with custom icons, badges, groups, and labels. Backup options give you a choice between cloud sync or manual exports, and Apple Watch support adds quick access without pulling out your phone. The app works entirely offline.

The password manager stores credentials locally and pairs with a browser extension that shares selected passwords with your browser securely. It supports three security tiers so you can tune how aggressively items are protected. Like tools such as Bitwarden or KeePassXC, it gives you self-hostable vault storage, but 2FAS combines that with a native mobile-first experience rather than a desktop-centric one.

Key capabilities across both tools:

• Local-first storage with self-hostable vault options
• Zero-knowledge design so 2FAS never sees your data
• On-device encryption where only you hold the keys
• No account required for fully anonymous use
• Browser extension for secure password sharing with selected sites
• Token customization with icons, labels, badges, and groups
• Offline operation with no dependency on external servers

The source code is public and accompanied by a Cryptography White Paper that documents the encryption algorithms and design decisions. That level of transparency puts it in different territory from closed-source alternatives like LastPass or 1Password.

Native iOS and Android apps keep the experience tight. The project is community-driven, with crowdsourced translations and an active Discord and GitHub presence. Over six million downloads and consistently high app store ratings reflect a user base that's stuck with it long-term.