Proton Authenticator is a free, open source two-factor authentication app that stores six-digit codes behind end-to-end encryption and syncs them across phones and desktops, with no ads and no tracking.
Proton Authenticator generates the one-time codes used for two-factor authentication and keeps them out of reach of everyone else. Setup is deliberately light: install the app, scan the QR code a service displays, and the entry joins the vault. There is no signup, email address, or phone number required to begin, and codes remain available without an internet connection, which matters on a plane or when a network is down. Optionally, signing in with a Proton account syncs the same vault across devices under end-to-end encryption. If a service does not offer a QR code, the secret can be typed in, and codes from other authenticator apps can be imported rather than re-added one by one.
The everyday use case is mundane, which is exactly the point. A prompt appears, you open the app, copy a six-digit code, and paste it before the timer runs out. That happens on a bank portal, a work email account, or a Cisco Webex Meetings sign-in, and it happens many times a week, so small frictions add up. Proton Authenticator answers that with search across entries, custom icons, widgets that surface codes without opening the app, and a preview of the next code so a login can start in the final seconds of the current one. Unlocking the vault itself uses a fingerprint or face scan instead of a typed password.
The first benefit of Proton Authenticator is that losing a phone does not mean losing accounts. Encrypted backups, tied to a Proton account or stored on the device, mean the vault can be restored rather than rebuilt from scratch, and codes can be exported to a separate secure location for the worst case. The second benefit of Proton Authenticator is portability. The same vault works on Android, iOS, Windows, Mac, and Linux, so a desktop login can be completed without reaching for a phone, while the app keeps working offline when the network does not cooperate. Import support matters just as much, because switching authenticators is the moment most people give up; codes come across from common apps instead of being re-enrolled service by service. Finally, the privacy stance is explicit: open source code anyone can inspect, no advertising, no tracking, and a company structured around privacy rather than data collection.
Key capabilities and highlights.
Proton Authenticator, like the rest of Proton's software, publishes its source code so anyone can inspect how codes are handled, and it carries no advertising or tracking, which removes the usual trade-off between a free tool and a private one. Nothing has to be paid to use it on any platform.
Signing in with a Proton account copies the vault to other devices under end-to-end encryption, so a code generated on a phone matches the one shown on a desktop and nothing is readable by the provider. The sync is optional; the app works without an account at all.
Codes inside Proton Authenticator are generated on the device from stored secrets rather than fetched from a server, so authentication still works with no connection, which matters on flights, in dead zones, or when an outage coincides with a login. The clock is the only thing the algorithm needs.
Enrolling a service takes a QR scan, and a secret can also be typed by hand when a site only offers text, so older or awkward setups are not left out of the two-factor workflow. Each entry is named as it is added, which keeps a growing list readable.
Proton Authenticator can bring codes over from common authenticator apps rather than requiring each service to be enrolled again, which is what makes switching practical for someone with dozens of accounts already protected. Import sources include Google Authenticator, 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, and LastPass Authenticator.
Codes can be exported to another secure location you choose, and encrypted backups protect the vault against a lost, stolen, or replaced device, so recovery does not depend on hunting down a long list of one-time recovery codes. Backups keep the same guarantees as the synced vault.
A search box, custom icons, and widgets make a long list of accounts navigable, and Proton Authenticator also displays the next code so a login can begin in the last seconds before the current one expires. These touches decide whether two-factor authentication feels like friction or routine.
Face or fingerprint unlock opens the vault without typing a password, which keeps codes quick to reach while still requiring something that belongs to you rather than something you know. It is the difference between using two-factor authentication properly and skipping it out of impatience.
Browse historical releases and previous builds.
Common questions about Proton Authenticator.
It is a two-factor authentication app that generates one-time codes for your logins. It is free, open source, works offline, and keeps codes under end-to-end encryption rather than in an advertising-funded account.
No. Proton Authenticator works without any account, email address, or phone number. A Proton account is only needed if you want codes synced and backed up across your devices.
Yes. Import is supported from several popular apps, including Google Authenticator, 2FAS, Aegis, Bitwarden Authenticator, Ente Auth, and LastPass Authenticator, and codes can be exported again afterwards.
Encrypted backups let the vault be restored to a new device, and codes can also be exported to another secure location as an extra safety net, so accounts are not locked behind a single handset.
Yes. Codes are generated locally from stored secrets, so no connection is required to read or use them at the moment a service asks for one.
Mobile apps cover Android and iOS, including iPad and Apple Watch, and there are desktop apps for Windows, Mac, and Linux, all sharing the same vault once you sign in with a Proton account.
Proton Pass is a password manager that also stores two-factor codes. The authenticator is a standalone app for people who only want the second factor and do not need a password vault alongside it.
Yes. The source is published so anyone can inspect how codes are protected, and the app includes no advertising or tracking, which is unusual for a free security tool.
Proton Authenticator is a free, open source two-factor authentication app that stores six-digit codes behind end-to-end encryption and syncs them across phones and desktops, with no ads and no tracking.
Element is a Matrix-based secure messenger and collaboration app with end-to-end encryption, group calls, and file sharing. It targets individuals, teams, and public institutions that want to self-host their own messaging network instead of renting one.
Nextcloud is a self-hosted collaboration platform whose desktop client keeps folders synchronised with your own server. It supports on-demand virtual files, selective sync, multiple accounts, end-to-end encrypted folders, and notifications from apps like Talk.
Microsoft Application Inspector is an open-source source code characterization tool that reports what a codebase actually contains, from cryptography and shell calls to cloud APIs, so teams can assess third-party components before trusting them.
Proton Drive is end-to-end encrypted cloud storage from Proton, the Swiss company behind Proton Mail. It encrypts files, photos, and documents on your device before upload, then syncs them across Windows, macOS, mobile, and the web.
Comments