Freedom251 › Authenticator apps
Stratum
What Stratum is
Stratum is a free, open-source two-factor authentication app for Android. It generates TOTP, HOTP, mOTP, Steam, and Yandex codes and works without Internet access. Passwords and biometric authentication can protect codes with encryption. Encrypted backups can be restored on a replacement phone. Stratum has no cloud synchronization, although Auto Backup can save files to a WebDAV server when used with DAVx5. Accounts can be imported from other authenticator apps when those apps permit export, and Stratum data can be exported. Organization tools include authenticator icons, categories, adjustable display density, accent colors, and ordering. A Wear OS companion displays codes synchronized from the phone, with an Android connection required for initial access. The project publishes auditable GitHub source under GPL 3.0 and says it has no corporate ties. The Google Play edition includes proprietary features; free-software releases are available through Stratum and IzzyOnDroid.
Who it suits
Stratum suits Android users seeking local, open-source two-factor authentication with encrypted backups and code organization. It is not available for iOS and probably will not be.
What it does well
- Supports multiple authentication code types
- Works without Internet access
- Offers encrypted backups
- Provides password and biometric protection
- Publishes source under GPL 3.0
What to know first
- No iOS version
- No cloud synchronization
- Imports depend on source-app export
- Wear OS does not support HOTP
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Stratum | Free and open-source; Google Play version includes proprietary features; free software releases available through Stratum and IzzyOnDroid repos | Free |
As stratumauth.com lists them, read 11 Oct 2026. The maker's own page has the final word.
Verdict
Stratum offers broad code support, local operation, encrypted backups, and an auditable open-source project. Android users should note its iOS absence, import dependencies, and platform-specific Wear OS limitation.
Facts from Stratum's own pages
- Account protection
- Users can set a password and use biometric authentication to protect codes with encryption. · stratumauth.com, 11 Oct 2026
- Codes
- It supports TOTP, HOTP, mOTP, Steam and Yandex authentication codes. · stratumauth.com, 11 Oct 2026
- Code type
- totp and hotp · stratumauth.com, 22 Sept 2026
- Encrypted backup
- Yes · stratumauth.com, 22 Sept 2026
- Encrypted backups
- Users can protect backup files with encryption and restore them on a replacement phone. · stratumauth.com, 11 Oct 2026
- Free plan
- Yes · stratumauth.com, 22 Sept 2026
- Import limitation
- Importing from another authenticator depends on that app allowing data export; the FAQ says Microsoft Authenticator does not export secrets. · stratumauth.com, 11 Oct 2026
- Local operation
- The app does not require Internet access to function and does not implement cloud sync. · stratumauth.com, 11 Oct 2026
- Migration
- Users can import accounts from supported alternative apps and export their data. · stratumauth.com, 11 Oct 2026
- Multi-device sync
- Yes · stratumauth.com, 22 Sept 2026
- Organization
- The app provides authenticator icons, categories, adjustable display density, accent colors and ordering. · stratumauth.com, 11 Oct 2026
- Platform limitation
- The FAQ says Stratum is not available for iOS and probably will not be. · stratumauth.com, 11 Oct 2026
- Privacy and source
- The project says it has no corporate ties, publishes auditable source code on GitHub, and uses the GPL 3.0 license. · stratumauth.com, 11 Oct 2026
- Purpose
- Stratum is a free and open-source two-factor authentication app for Android. · stratumauth.com, 11 Oct 2026
- Support
- The feedback form does not provide support; it directs users to the FAQ and suggests filing bugs on GitHub. · stratumauth.com, 11 Oct 2026
- Supported platforms
- android · stratumauth.com, 22 Sept 2026
- Wear OS
- A Wear OS companion displays codes synced from the phone, and requires a connection to the Android device for initial access. · stratumauth.com, 11 Oct 2026
- Wear OS limitation
- The FAQ says HOTP is not supported on the Wear OS app because its counter cannot be reliably reported back to the phone. · stratumauth.com, 11 Oct 2026
- WebDAV backup
- Auto Backup can save files to a WebDAV server when used with the DAVx5 app. · stratumauth.com, 11 Oct 2026
Where Stratum stands on Freedom251
- Authenticator apps#72 of 111