Otter 2FA Authenticator

Otter generates your two-factor authentication codes on your phone, from keys that stay on your phone. No account. No cloud. No server.

Nothing to create, no extra password, nothing to confirm by email. The Android app on this store does not even hold the permission required to reach the network, so "your codes never leave your device" is something the operating system enforces rather than something we ask you to believe.

MOVING IN, AND MOVING ON
- Reads the standard otpauth setup codes any other authenticator can export
- Exports one encrypted backup file, sealed with a passphrase you choose
- Import adds to what you have, or replaces it, and tells you which before it acts
- The backup holds standard URIs, so it stays readable elsewhere if you ever leave

WHAT IT DOES
- Adds accounts by scanning a QR code, or by typing the key by hand
- Generates standard TOTP and HOTP codes, as used by every major service
- Groups the digits 3+3 and shows the seconds left, so nothing jumps as it changes
- Copies a code with one tap, and clears the clipboard afterwards
- Hides codes until you tap them, and can block screenshots

HOW YOUR KEYS ARE KEPT
- Every key is encrypted with AES-256-GCM before it touches the disk
- The key that opens them is held by your phone's own secure hardware, behind Face ID, Touch ID or a PIN
- A wrong PIN slows down the next attempt, and the delay survives a restart
- Otter shows codes, never the keys behind them

THE REST
- Free. No adverts, no subscription, no in-app purchase, no paid tier
- English and French, following whichever your phone is set to
- Ten app icons, and a true black dark mode for OLED screens
- No analytics, no crash reporting, no telemetry of any kind

WHAT IT PROTECTS YOU AGAINST
- A lost or stolen phone, locked
- Someone picking up your phone while it is unlocked
- Someone reading the app's data directory, or an unencrypted device backup
- Screenshots and shoulder-surfing
- A leaked backup file, without its passphrase
- Silent tampering with the stored data

WHAT IT CANNOT PROTECT YOU AGAINST
- A rooted or jailbroken phone, or its memory read while the vault is open
- A compromised operating system, or a compromised keyboard
- Someone coercing you into unlocking it
- A PIN or a backup passphrase that is easy to guess

And the backup is the only way back. If you lose your phone without one, the keys are gone: Otter holds no copy, so there is nothing on our side to restore from. Export one on the day you install.