Proton Authenticator

Proton Authenticator creates time-based, one-time codes for two-factor login security. Codes remain available offline, and using the app does not require a Proton Account. Signing in is optional and allows codes to sync across devices. The app can import codes from Google Authenticator, 2FAS, Aegis Authenticator, Bitwarden Authenticator, Ente Auth and LastPass Authenticator, and it also supports exporting codes.

Users can back up codes locally or in the cloud. Proton says synced data is end-to-end encrypted and inaccessible to its servers in unencrypted form; when sync is enabled, entries use 256-bit AES-GCM encryption. The app is open source, and its vault can be unlocked with face or fingerprint recognition. Proton lists versions for Android, iOS, Linux, macOS and Windows, with Android also available on F-Droid. The app is free on all listed platforms, with no ads or tracking.

Proton Authenticator offers offline codes, import and export, and optional encrypted multi-device sync at no cost. Its listed platform support spans desktop and mobile systems.

It suits people who want offline access to login codes or need to move codes between authenticator apps. Optional encrypted sync is available for those who use multiple devices.

Proton Authenticator generates time-based codes for people adding a second factor to account logins. It suits users who want an authenticator on both phones and computers, with no charge and optional encrypted sync. Its import and export options make it a practical choice for moving between services, though anyone who specifically wants a hardware-key-based authenticator should look elsewhere.

Overview

The app generates one-time codes on the device and can display them without an internet connection. A Proton Account is optional: you can use the authenticator without one, but signing in enables syncing codes across devices. That is a useful distinction for people who want a standalone app on one device, while syncing requires opting into an account.

Proton Authenticator is open source, and its vault can be unlocked with face or fingerprint recognition. These are meaningful options for users who value inspectable software or want a biometric gate to the vault; neither changes the need to protect the accounts secured by the codes.

Key features

Move codes in and out

Proton Authenticator imports codes from Google Authenticator, 2FAS, Aegis Authenticator, Bitwarden Authenticator, Ente Auth, and LastPass Authenticator. That breadth can reduce the friction of switching from a range of existing apps. Export is also supported, giving users a way to take their codes elsewhere if their preferences change.

Backup and encrypted sync

You can back up codes locally or in the cloud. When sync is enabled, entries use 256-bit AES-GCM encryption, and Proton says its servers cannot access the unencrypted data. This offers a clear privacy distinction for people who want codes on more than one device; users who prefer not to sign in can keep using the app without sync.

Pricing

Proton Authenticator is free on all platforms, with no ads or tracking. There is no free trial because the free plan is the product's only listed plan. That makes it suitable for anyone seeking a no-cost authenticator without a paid tier to unlock core availability; there are no published plan quotas or seat limits to weigh.

Platforms

Apps are available for Android, iOS, Windows, macOS, and Linux. The Android app is also available through F-Droid. Support across desktop and mobile is useful for people who move between computers and phones, while offline code display helps when an internet connection is unavailable.

Who it's for

This is a strong fit for people who want a free TOTP app with offline access, a broad set of import sources, and the choice of local use or encrypted multi-device sync. Open-source availability and biometric vault unlocking may also matter to users who value code inspection or a biometric access gate. It is less suitable for someone seeking a hardware-key-based approach.

Pros and cons

• Pros: Free across desktop and mobile, with no ads or tracking, so cost and platform coverage are straightforward.
• Pros: Imports from six named authenticator apps and supports export, making migration in either direction more practical.
• Pros: Offline codes and optional end-to-end encrypted sync let users choose between standalone use and cross-device access.
• Cons: Sync requires signing in with a Proton Account, which may not suit users who want synchronized codes without an account.
• Cons: It is a software-code authenticator, not a hardware-key-based option, so it will not fit users who specifically require that approach.

Alternatives

Authenticator apps is a useful place to compare more options. Choose Duo Mobile if you want a freemium service with a free plan for 10 users or are considering its $3 a month Duo Essentials plan, which includes Duo Directory, phishing-resistant MFA, and passwordless authentication.

Yubico Authenticator is the alternative to consider if you want free, open-source software that requires a YubiKey to store credentials and generate codes. Zoho OneAuth is another free option for Zoho work accounts and personal online accounts.

Bitwarden is worth considering if you want to explore a freemium password manager with a free plan. Ente Auth is a free, open-source alternative that supports importing and exporting data. Authy is a free option with encrypted cloud backup and multi-device support.

SAASPASS Authenticator offers a freemium plan for personal mobile use. Salesforce Authenticator is a free mobile option with MFA verification, push notifications, and TOTP codes.

Verdict

Proton Authenticator is an easy recommendation for users who want free codes across phones and computers, the freedom to use it offline, and optional encrypted sync. Its strongest practical advantage is the combination of broad imports and an export path, which makes it less of a commitment than an authenticator that is difficult to leave. Look elsewhere if your priority is a hardware-key-based authenticator.