Proton Authenticator review: private codes across devices

Proton Authenticator is a free, open-source authenticator app for sign-in codes. Proton says you can keep those codes separate from your passwords, and you can use the app without a Proton Account.¹ Start with one service, make a backup, and turn on syncing only if you want the codes on a second device.

Last checked October 28, 2026.

At a glance

What it is: A standalone app for two-factor sign-in codes.¹

Works on: Android, iOS, Windows, Mac and Linux.¹

Price: Free to use on every platform Proton lists.¹

Licence: GNU GPL version 3 or later for the Android client.²

Best for: People who value a separate place for codes and a choice about cloud syncing.

Official site: Proton Authenticator

What Proton Authenticator does and how it protects your privacy

The app generates time-based one-time passwords, usually called TOTP codes.⁵ These are temporary numbers used as an extra sign-in check. Proton describes entering a fresh six-digit code when you log in.¹ Think of it as an extra step between entering your password and opening your account.

You can use the app without a Proton Account.¹ Syncing is optional. On Apple devices it can go through iCloud; on Windows, Linux and Android it needs a Proton Account.⁶ Decide which matters more: keeping the arrangement simple on one device, or having another device ready when you need it. Neither choice removes the need to plan recovery.

The apps are still being updated. The Android changelog’s newest numbered entry is 1.3.10, dated July 22, 2026.³ The Apple listing shows 1.4.5 on October 14, while the desktop changelog lists 1.1.6.⁷⁸ F-Droid separately offers Android version 1.3.9, added July 15, 2026.⁴ Use the update channel you installed from; these numbers describe different builds, rather than one universal version.

Proton Authenticator key features

Offline codes: Access codes without an internet connection.¹
Optional syncing: Choose whether to make codes available across devices.⁶
Password-protected backups: Android supports creating backups protected with a password.³
Encrypted transfers: The desktop app supports encrypted import and export.⁸
Automatic backups: Desktop releases support encrypted automatic backups.⁸
Search: Find an account without scrolling through every entry.¹

Proton Authenticator pros and cons

Pros

You can add an extra sign-in step while keeping the codes in their own app.
Passwords can stay in a password manager, with the codes kept separately.
The same codes can be reached on a phone and on a computer.
Backup and export options give you a copy you can move later.

Cons

There is still setup work: take time to enable protection on each account.
Cloud choices differ: Proton documents iCloud syncing for Apple devices and Proton-account syncing for Windows, Linux and Android.⁶
Older phones have limits: F-Droid’s current build requires Android 8.1 or newer.⁴
F-Droid says the app tracks and reports your activity, that users are fingerprinted even when online features are off, and that the backend is proprietary.⁴

Is Proton Authenticator safe and private?

The developer is Proton AG.⁷ According to Proton’s security model, encryption is performed on the device, and Proton cannot access the unencrypted entries.⁵ End-to-end encryption means information is scrambled before it leaves your device and unlocked at the receiving end.

Privacy also includes app reporting. Apple’s developer-supplied label lists diagnostics that may be collected without being linked to your identity.⁷ The Android changelog documents a setting for enabling or disabling anonymous data sharing.³ Proton’s product page says the app has no ads and no tracking.¹ Review that setting before adding accounts. F-Droid’s warnings describe app connections; they do not say that encrypted account entries are readable.

For independent scrutiny, Proton’s security-model page says Authenticator will undergo independent audits and that reports will be shared when available.⁵ That is a commitment, not a published audit result. Keep the app and device updated, use a strong device lock, and make recovery part of your setup.

How to get started with Proton Authenticator

Choose an official download. Follow the platform link from the official site above. On Android, F-Droid is another documented distribution channel.⁴ Prefer an update-capable store or client over an unfamiliar download mirror.
Begin with one account. Open that service’s security settings and enable two-factor authentication.⁶ Start with an account you can recover comfortably.
Add its code. In Proton Authenticator, scan the service’s QR code or enter its secret key manually.⁶ Give the entry a recognizable name; do not share the setup key or QR image.
Try a sign-in. Complete the service’s confirmation step, then try signing in again. Keep your original session open until you are satisfied the new arrangement works.
Prepare recovery. Save any recovery codes the service offers somewhere accessible if your phone is lost. Create an encrypted backup and keep its password separately. For more backup planning, see the Academy’s Duplicati guide.
Move gradually. If importing existing entries, test them before removing the old app. Choose a sync arrangement deliberately and confirm that your second device has the entries you expect.

Who should use Proton Authenticator?

Proton Authenticator is worth considering if you want a dedicated code app and desktop access alongside your phone. You can begin on one device and decide about syncing later. Choose an arrangement you understand and can recover.

If another interface feels easier, compare the Academy guides to 2FAS Auth and FreeOTP. Before switching, compare their current download requirements, backup steps and recovery options against your own devices.

Frequently asked questions

Is Proton Authenticator free?

Yes: Proton describes it as free to use.¹ Choose your backup and recovery arrangement before relying on it for important accounts.

Does Proton Authenticator work on iPhone?

Yes; the App Store listing requires iOS 17.0 or later.⁷ Check compatibility on the device you plan to use before moving your codes.

Do I need a Proton account?

No. Proton says you can use Proton Authenticator without an account.¹ Syncing is a separate choice, and installing the app is not the same as having a tested recovery plan.

How can I prepare for losing my phone?

Keep recovery codes outside the phone and arrange a backup before you need one. The desktop app supports encrypted automatic backups.⁸ Check that your chosen copy is accessible from another device, and keep the password needed to open it somewhere safe.