--- title: Proton Authenticator canonical: https://saasranked.com/software/proton-authenticator/ category: Authenticator Apps points: 79 rank: 2 of 12 facts_checked: 2026-10-08 --- # Proton Authenticator Free, open-source two-factor code app with end-to-end encrypted sync and apps for five systems. 79 points out of 100. #2 of 12 authenticator apps. Vendor: Proton. Website: https://proton.me/authenticator - The app is free on all platforms and works without a Proton Account [1]. - Native apps cover Windows, macOS, Linux, iOS and Android [2]. - Backups use a key derived from your password with Argon2, and synced codes are end-to-end encrypted [3]. - Syncing between Windows, Linux and Android needs a Proton Account; Apple devices can use iCloud [5][6]. - Proton says it plans independent audits but names no audit of this app yet [3]. Verdict: Proton Authenticator suits people who want codes on a phone and a desktop, with encrypted backup and no paid plan [1][2][3]. It imports from several rival apps and exports your codes [1][7]. The catch: Proton names no outside audit of this app yet, and Proton's pages do not mention passkeys, push approval or counter-based codes [1][3]. Best for: People who want encrypted sync and a Windows or Linux app. ## Points | Criterion | Line | Value | Points | Note | |---|---|---|---|---| | Security and trust | End-to-end encrypted backup | Yes | 12/12 | Backups use a key derived from your password with Argon2; synced data is end-to-end encrypted with your key [3]. | | Security and trust | Independent audit, 2023 or later | Not published | 0/10 | Not published on the vendor's security-model and open-source pages [3][10]; Proton says audits will come. | | Security and trust | Open-source apps | Yes | 6/6 | Proton says the app is open source [3]; the iOS and Android repositories are listed under the GNU GPL v3.0 [9]. | | Security and trust | Public bug bounty | Yes | 3/3 | Proton says the app is eligible for its bug bounty programme [3]; the programme has its own page [11]. | | Security and trust | App lock | Yes | 6/6 | Lock the app with biometrics or a PIN, with an automatic lock timer [4]. | | Backup and recovery | Cloud backup or sync | Yes | 10/10 | Back up to iCloud on Apple devices or a chosen location on Android [8]; Proton Account sync also works [6]. | | Backup and recovery | Same codes on several devices | Yes | 7/7 | Sync between devices with a Proton Account, or iCloud on Apple devices [6]. | | Backup and recovery | Export all accounts | Yes | 7/7 | The app page says you can export your codes to a location of your choice [1]. | | Backup and recovery | Import from other apps | Yes | 6/6 | Import guide covers CSV files, QR codes and exports from 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, Google Authenticator and LastPass Authenticator [7]. | | Backup and recovery | Works without an account | Yes | 5/5 | The help centre says a Proton Account is not needed to use the app [5]. | | Systems | Apps | Windows, macOS, Linux, iOS, Android | 10/12 | Download page lists desktop apps for Windows, macOS and Linux, plus iOS and Android; no web app [2]. | | Features | Stores passkeys | Not published | 0/3 | Not published on the vendor's app and help pages [1][5]. | | Features | Sign-in approval prompts | Not published | 0/3 | Not published on the vendor's app and help pages [1][5]. | | Features | Counter-based (HOTP) codes | Not published | 0/3 | Not published; the security-model page mentions only time-based codes [3]. | | Features | Folders, tags or search | Yes | 3/3 | The app page says you can find accounts with search and custom icons [1]. | | Price | Cost with backup on two devices | $0 | 4/4 | Proton says the app is completely free on all platforms [1]; sync uses a Proton Account or iCloud [6]. | ## Plans | Plan | Price | Per month (USD) | |---|---|---| | Free | Free [1][5] | $0 | ## Strengths - Free, with no ads or tracking claimed, and no account needed to use it [1][5]. - Apps for Windows, macOS, Linux, iOS and Android [2]. - Backups are encrypted with a key derived from your password [3]. - Imports from 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, Google Authenticator and LastPass Authenticator [7]. - Biometric or PIN lock with an auto-lock timer [4]. ## Limits - Proton says audits will follow; no audit of this app is named [3][10]. - Sync across Windows, Linux and Android needs a Proton Account [5]. - No web app is listed [2]. - In August 2025 the iOS app wrote codes' secrets to local debug logs until version 1.1.1 [12]. ## Vendor claims (not scored) - Proton says nobody but you, not even Proton, can access your codes [5]. - Proton says the app will undergo regular independent security audits, with reports shared as they become available [3]. ## Concerns - BleepingComputer reported on 4 August 2025 that the iOS app wrote full TOTP secrets to its local debug logs; Proton fixed it in version 1.1.1 and told the outlet the logs are local only and never sent to its server [12]. ## Sources 1. [Proton Authenticator](https://proton.me/authenticator), Proton, accessed 2026-10-08 2. [Download Proton Authenticator](https://proton.me/authenticator/download), Proton, accessed 2026-10-08 3. [Proton Authenticator security model](https://proton.me/blog/authenticator-security-model), Proton, accessed 2026-10-08 4. [Proton Authenticator security](https://proton.me/authenticator/security), Proton, accessed 2026-10-08 5. [Proton Authenticator FAQs](https://proton.me/support/proton-authenticator-faqs), Proton, accessed 2026-10-08 6. [Sync your 2FA codes](https://proton.me/support/sync-2fa-codes), Proton, accessed 2026-10-08 7. [Import 2FA codes](https://proton.me/support/import-2fa-codes), Proton, accessed 2026-10-08 8. [Back up 2FA codes](https://proton.me/support/back-up-2fa-codes), Proton, accessed 2026-10-08 9. [Proton Pass repositories](https://github.com/orgs/protonpass/repositories), GitHub, accessed 2026-10-08 10. [Open source](https://proton.me/community/open-source), Proton, accessed 2026-10-08 11. [Bug bounty programme](https://proton.me/security/bug-bounty), Proton, accessed 2026-10-08 12. [Proton fixes Authenticator bug leaking TOTP secrets in logs](https://www.bleepingcomputer.com/news/security/proton-fixes-authenticator-bug-leaking-totp-secrets-in-logs/), BleepingComputer, accessed 2026-10-08