Proton Authenticator

Proton Authenticator is an open-source and end-to-end encrypted software-based authenticator. When logging into a website or application that supports multi-factor authentication, the user will be prompted for a six-digit one-time password which changes every thirty seconds. Proton Authenticator displays the current six-digit code, the next six-digit code, and the remaining number of seconds until the current code expires.

Proton Authenticator
Developer(s)	Proton AG
Initial release	July 31, 2025; 2 days ago (2025-07-31)
Repository	Android repo iOS repo
Written in	Kotlin (Android) Swift (iOS)
Operating system	Android, iOS, Windows, macOS, Linux
Platform	Mobile, Desktop
License	GNU General Public License v3
Website	proton.me/authenticator

Proton Authenticator is available on iOS, Android, macOS, Windows, and Linux.^[1]

License

Proton Authenticator is licensed under GNU General Public License version 3.^[2]

See also

• Free and open-source software portal

• Proton Pass – Proton AG’s password manager that includes built‑in 2FA
• Proton Mail, Proton VPN, Proton Drive — other services in Proton’s encrypted ecosystem
• Google Authenticator
• Multi-factor authentication
• Comparison of OTP applications