saasrankedSoftware, ranked on the facts

authenticator app · Proton

Proton Authenticator

Free, open-source two-factor code app with end-to-end encrypted sync and apps for five systems.

79/100

#2 of 12 authenticator apps
Facts checked 8 Oct 2026

In short

Proton Authenticator suits people who want codes on a phone and a desktop, with encrypted backup and no paid plan1,2,3. It imports from several rival apps and exports your codes1,7. The catch: Proton names no outside audit of this app yet, and Proton's pages do not mention passkeys, push approval or counter-based codes1,3.

Best for: People who want encrypted sync and a Windows or Linux app.

Where the points come from

Security and trust27 of 37
Backup and recovery35 of 35
Systems10 of 12
Features3 of 12
Price4 of 4

Security and trust 27 of 37 points

RuleWhat is publishedPoints
End-to-end encrypted backupYesBackups use a key derived from your password with Argon2; synced data is end-to-end encrypted with your key3.12 / 12
Independent audit, 2023 or laterNot publishedNot published on the vendor's security-model and open-source pages3,10; Proton says audits will come.0 / 10
Open-source appsYesProton says the app is open source3; the iOS and Android repositories are listed under the GNU GPL v3.09.6 / 6
Public bug bountyYesProton says the app is eligible for its bug bounty programme3; the programme has its own page11.3 / 3
App lockYesLock the app with biometrics or a PIN, with an automatic lock timer4.6 / 6

Backup and recovery 35 of 35 points

RuleWhat is publishedPoints
Cloud backup or syncYesBack up to iCloud on Apple devices or a chosen location on Android8; Proton Account sync also works6.10 / 10
Same codes on several devicesYesSync between devices with a Proton Account, or iCloud on Apple devices6.7 / 7
Export all accountsYesThe app page says you can export your codes to a location of your choice1.7 / 7
Import from other appsYesImport guide covers CSV files, QR codes and exports from 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, Google Authenticator and LastPass Authenticator7.6 / 6
Works without an accountYesThe help centre says a Proton Account is not needed to use the app5.5 / 5

Systems 10 of 12 points

RuleWhat is publishedPoints
AppsWindows, macOS, Linux, iOS, AndroidDownload page lists desktop apps for Windows, macOS and Linux, plus iOS and Android; no web app2.10 / 12

Features 3 of 12 points

RuleWhat is publishedPoints
Stores passkeysNot publishedNot published on the vendor's app and help pages1,5.0 / 3
Sign-in approval promptsNot publishedNot published on the vendor's app and help pages1,5.0 / 3
Counter-based (HOTP) codesNot publishedNot published; the security-model page mentions only time-based codes3.0 / 3
Folders, tags or searchYesThe app page says you can find accounts with search and custom icons1.3 / 3

Price 4 of 4 points

RuleWhat is publishedPoints
Cost with backup on two devices$0Proton says the app is completely free on all platforms1; sync uses a Proton Account or iCloud6.4 / 4

The rule behind each line: how we score authenticator apps.

Plans and prices

As the vendor lists them, before tax. Prices are in US dollars unless the plan shows euros; the points use US dollars, with euros converted at the ECB rate.

PlanPrice as listedPer monthNotes
Free1 personFree1,5$0All features, all platforms; sync across Windows, Linux and Android needs a Proton Account

Strengths

  • Free, with no ads or tracking claimed, and no account needed to use it1,5.
  • Apps for Windows, macOS, Linux, iOS and Android2.
  • Backups are encrypted with a key derived from your password3.
  • Imports from 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, Google Authenticator and LastPass Authenticator7.
  • Biometric or PIN lock with an auto-lock timer4.

Limits

  • Proton says audits will follow; no audit of this app is named3,10.
  • Sync across Windows, Linux and Android needs a Proton Account5.
  • No web app is listed2.
  • In August 2025 the iOS app wrote codes' secrets to local debug logs until version 1.1.112.

Concerns on record

  • 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 server12.

What Proton says

Vendor claims. We show them, but they earn no points.

  • Proton says nobody but you, not even Proton, can access your codes5.
  • Proton says the app will undergo regular independent security audits, with reports shared as they become available3.

Other authenticator apps

  1. 1
    Ente AuthPeople who want encrypted sync, open source and a web view of their codes
    91/100
    $0cost with backup on two devices
  2. 3
    Zoho OneAuthPeople who want free encrypted backup and the same codes on a phone and a computer
    74/100
    $0cost with backup on two devices
  3. 4
    2FAS AuthiPhone and Android users who want a free app without an account
    73/100
    $0cost with backup on two devices
  4. 5
    StratumAndroid users who want an offline, open-source app they fully control
    60/100
    Not publishedcost with backup on two devices

Proton Authenticator vs Ente Auth · Proton Authenticator vs Zoho OneAuth · All 12 authenticator apps

Sources

  1. Proton Authenticator, Proton. Accessed 8 Oct 2026.
  2. Download Proton Authenticator, Proton. Accessed 8 Oct 2026.
  3. Proton Authenticator security model, Proton. Accessed 8 Oct 2026.
  4. Proton Authenticator security, Proton. Accessed 8 Oct 2026.
  5. Proton Authenticator FAQs, Proton. Accessed 8 Oct 2026.
  6. Sync your 2FA codes, Proton. Accessed 8 Oct 2026.
  7. Import 2FA codes, Proton. Accessed 8 Oct 2026.
  8. Back up 2FA codes, Proton. Accessed 8 Oct 2026.
  9. Proton Pass repositories, GitHub. Accessed 8 Oct 2026.
  10. Open source, Proton. Accessed 8 Oct 2026.
  11. Bug bounty programme, Proton. Accessed 8 Oct 2026.
  12. Proton fixes Authenticator bug leaking TOTP secrets in logs, BleepingComputer. Accessed 8 Oct 2026.

Website: proton.me/authenticator · Markdown version · We are not affiliated with Proton.