Independent reviews of 2FA apps based on local storage, open-source code, backup options, and actual privacy practices—not affiliate commissions.
| App | Local Storage | Open Source | Encrypted Backup | Cloud Sync | Verdict | Details |
|---|---|---|---|---|---|---|
| Aegis (Android) | Yes | Yes | Yes | None | Recommended | Read Review → |
| Raivo (iOS) | Yes | Yes | Yes | Optional (iCloud) | Recommended | Visit Site |
| Bitwarden Authenticator | Yes | Yes | Yes | None | Recommended | Visit Site |
| Google Authenticator | No | No | No | Yes (unencrypted) | Avoid | Visit Site |
Local storage means codes never leave your device by default. Cloud sync is optional in most apps but introduces a potential exposure point.
Your 2FA codes should be stored only on your device, not synced to a cloud service by default. Cloud sync adds convenience but creates a single point of failure — if your cloud account is compromised, so are your second factors.
A closed-source 2FA app requires trusting the developer completely. Open-source apps can be audited to verify they store and generate codes as claimed, with no hidden syncing or telemetry.
Without a backup, losing your phone means losing access to all your 2FA-protected accounts. Look for apps that support encrypted export so you can securely back up your tokens and restore them on a new device.
A 2FA app that requires creating an account with the developer links your authentication codes to a third-party account. The best apps work entirely without an account.
SMS-based two-factor authentication is vulnerable to SIM swapping attacks, where an attacker convinces your carrier to transfer your number to their SIM. TOTP apps generate codes locally and cannot be intercepted this way. Always prefer an authenticator app over SMS when available.
Google Authenticator backs up codes to your Google account by default — without end-to-end encryption. This means Google can access your 2FA tokens, and anyone who compromises your Google account gets your second factors too.
If you lose your phone without a backup, you may be permanently locked out of accounts. Export an encrypted backup immediately after setup and store it somewhere safe — your password manager, a USB drive, or printed and stored physically.
For high-value accounts, hardware security keys like YubiKey are more phishing-resistant than TOTP apps. TOTP codes can be phished in real-time; hardware keys cannot. Consider hardware keys for your most critical accounts.
Android: Aegis — the strongest option, fully offline and open-source.
iOS: Raivo — the best iOS-native open-source option.
Both platforms: Bitwarden Authenticator is a solid cross-platform choice.
Start with your most important accounts: email, password manager, banking, and any accounts with sensitive data.
When setting up 2FA, scan the QR code with your chosen app. Also save the backup codes provided by the service — store these in your password manager or physically.
Export an encrypted backup from your 2FA app immediately after setup. Store this in at least two places — your password manager and a separate physical location.
Test the backup by restoring it on another device before you actually need it.
If you have a backup of your 2FA vault, you can restore all codes on a new device. If you don't, you'll need to use account recovery codes for each service — which is why saving backup codes when enabling 2FA is critical. Some services allow identity verification to recover access, but this is slow and not guaranteed.
Bitwarden and other password managers support storing TOTP codes alongside passwords. This is convenient but combines your first and second factors in one place — if your password manager is compromised, both are exposed. For most people this is an acceptable trade-off. For high-risk accounts, keep 2FA in a separate app.
TOTP generates a time-based six-digit code that changes every 30 seconds. Hardware keys (FIDO2/WebAuthn) use public-key cryptography and physically verify the site you are logging into — a fake phishing site cannot steal the credential. Hardware keys are more phishing-resistant. Use them for your most critical accounts where possible.
Google Authenticator has an export function that generates a QR code. Aegis can import this directly. Do this before your next device upgrade — once imported into Aegis, you can stop using Google Authenticator entirely.