Proton Authenticator is a free, private 2FA authenticator app that generates secure one-time passwords (OTP) on all your devices, even offline. Add multi-factor authentication (MFA) to your online accounts in seconds. From the creators of Proton Mail, Proton VPN, Proton Drive, and Proton Pass. Open-source, end-to-end encrypted, and protected by Swiss privacy laws, Proton Authenticator is the safest way to generate and store your 2FA codes and TOTP tokens. WHY CHOOSE PROTON AUTHENTICATOR? Free authenticator app: no Proton account required, no ads Works offline: generate OTP codes on mobile and desktop without a connection Encrypted sync: keep your 2FA codes on all your devices with end-to-end encryption Automatic backups: never lose access to your MFA-protected accounts Easy import and export: move your OTP tokens from other 2FA apps in a few taps, or export them anytime App lock: secure your authenticator app with biometrics or a PIN code Open source: transparent, verifiable code Swiss privacy: protected by Switzerland's privacy laws Trusted by millions. Built by Proton. Secure every login with a private 2FA authenticator app. Download Proton Authenticator today.