Proton V4 web beta brings persistent single sign-on in huge step toward full integration

Proton 4.0 is now in beta

Today, we are marking a major milestone in our mission to expand privacy online with the launch of a new beta version of ProtonMail for web that includes crucial new features like Single Sign-On and persistent sessions (“remember me”). 

Today’s updates create the foundation of a fully integrated, private, and encrypted ecosystem covering all basic internet needs in a way that puts people first. These improvements are first coming to the web apps, but in the coming quarters they will also make it to mobile as we launch more apps and features that protect your digital privacy.

To achieve this, we have completely rebuilt our web apps using a new programming framework that will tie all our apps together. 

This beta update also includes new ProtonMail features, such as subfolders and multi-account access. And last but not least, we are deploying ProtonDrive in closed beta for Lifetime account users.

While some of these new features and beta products are available only to users with paid plans, anyone can take advantage of the convenience of Single Sign-On and persistent sessions. To access them, go to and sign in to your Proton account.

Access all Proton services with just one login

Single Sign-On and persistent sessions make it possible to quickly access ProtonMail, ProtonCalendar, ProtonDrive, and ProtonContacts and use them as a connected suite of tools. 

With Single Sign-On and persistent sessions, you don’t need to enter your username, password, and two-factor authentication every time you switch between apps or reopen your browser. You can simply sign in to your Proton account and start working in ProtonMail or ProtonCalendar while keeping your data secure.

Single Sign-On

Single Sign-On allows you to easily switch between ProtonMail, ProtonContacts, ProtonCalendar, and eventually ProtonDrive without having to sign in again. 

For the time being, ProtonVPN is being kept separate to give it stronger censorship resistance, as in certain countries ProtonVPN is used to access the rest of the Proton services. While Single Sign-On is currently available only for Proton web apps, we will eventually include it in our Android and iOS apps. 

Persistent sessions

The new beta will also include persistent sessions for our web apps. This allows you to sign in to Proton, close your browser, and return later to your ProtonMail, ProtonCalendar, and eventually ProtonDrive without signing in again. For security reasons, your session will have a limited lifetime of 60 days if you are inactive, meaning you might need to log in again if you do not use one of our web apps for several weeks. That’s why it is critical to always remember your password.

This feature is automatic. In practical terms, it means you will be able to go straight into your Proton account first thing in the morning without entering your login credentials at the start of every day.

Note: If you are using a shared device or are concerned about physical device compromise, you should log out of your Proton account to end your session. Closing the tab is no longer sufficient.

We completely rebuilt ProtonMail from the ground up

While you will quickly notice the new Single Sign-On feature, some of our most significant changes are invisible to users. We have written the new ProtonMail beta, as well as all our other new products, using the React programming framework. 

This is a crucial step that lays the foundation upon which we can build a fully integrated Proton suite in the future. Using React makes it much easier to incorporate ProtonMail with ProtonContacts, ProtonCalendar, and ProtonDrive, as well as any future Proton tools. Because of these changes, we will be able to design features that let you seamlessly move events from your inbox to your calendar or share files with your contacts.

Throughout this process, we have also improved our code to make it more maintainable. While this type of work does not generally result in noticeable user benefits, it is important to build a sound footing now in the early years of Proton, which will accelerate the delivery of updates and new features in the future and provide better performance for our users.


The new ProtonMail beta will also let you organize your messages into subfolders. You can add subfolders to any “parent” folder, and you will be able to make subfolders within subfolders (the maximum number of folder levels is three). Subfolders have been a popular request from ProtonMail users, and we are making them available to everyone, including free users. 

Multi-account access

The new ProtonMail beta will also include our multi-account feature, which allows you to be signed in to an unlimited number of accounts at the same time. This makes it easy to quickly manage multiple accounts, which is particularly useful for:

  • Business owners, who can quickly toggle through their different, role-based email accounts, responding to questions in support@, sales@, and admin@. 
  • Workers, who can easily switch between their personal and professional inboxes. 
  • Freelancers, who can create inboxes dedicated to important clients, allowing them to separate their workflows and stay organized.

ProtonDrive early access

After months of internal testing, we are ready to share ProtonDrive beta with our Lifetime account holders. If you have a Lifetime account, thank you for your exceptional support of our mission. You will shortly receive an email detailing how to start testing our encrypted cloud storage solution. 

We will then extend this early access beta to Visionary users before opening it up to all users with paid accounts. 

ProtonDrive will greatly expand the possibilities of the Proton suite and make it simple to privately store and share sensitive files. You can read more about how ProtonDrive will secure your files in the ProtonDrive security model

The next frontiers of freedom

One of the challenges of making privacy-focused tools is that they must be both secure and easy to use. The most secure email service in the world can’t protect any data if it is too complex for most people to use. The new ProtonMail beta is the first step toward a unified Proton that eliminates unnecessary steps and allows for the frictionless exchange of encrypted files and information between different Proton apps. 

Screenshot of ProtonDrive.

Thank you to all our users. Your support is what makes our work possible. As with all our betas, we rely on your feedback to help us improve Proton. During the beta, you can send us your comments and feedback on the new ProtonMail inside the web app

To report issues, click Help > Report bug.

And let us know what you think of the Single Sign-On, multi-account support, and subfolder features in the new ProtonMail beta on Twitter, Facebook, Reddit, Instagram, Linkedin, and Mastodon.

This is the next step toward building an internet where user privacy is the default. Thank you for helping us move online security, privacy, and freedom forward.

You can get a free secure email account from ProtonMail here.

We also provide a free VPN service to protect your privacy. ProtonMail and ProtonVPN are funded by community contributions. If you would like to support our development efforts, you can upgrade to a paid plan. Thank you for your support.

Feel free to share your feedback and questions with us via our official social media channels on Twitter and Reddit.

About the Author

Proton Team

Proton was founded by scientists who met at CERN and had the idea that an internet where privacy is the default is essential to preserving freedom. Our team of developers, engineers, and designers from all over the world is working to provide you with secure ways to be in control of your online data.

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35 comments on “Proton V4 web beta brings persistent single sign-on in huge step toward full integration

  • I totally mis-read the headling and thought this meant that ProtonMail was going to support external SSO providers like SAML. Which would have been a lot cooler IMO.

  • This is a great step forward towards a unified Proton universe. I’m particularly eager to try Proton Drive in a near future.
    About this the persistent sessions, I’m sure it will need to have a persistent cookie from one session to the next, is that right?

  • I’m very impressed with this release, and love having my calendar and contacts available on separate tabs. Congratulations to the team!

  • Will the beta also include a fix for cross platform app syncing of unread messages? Say I have an unread message and read it on my desktop, the notification on my phone should disappear without me having to open the app. This is a bad UX if I have to do this for every device that I have the ProtonMail app installed.

  • thx for the update, i can finally use 2 factor, also hope u can add the custom theme back soon :v

  • I think persistent sessions should be opt-in rather than requiring user action to log out every single time. It’s a significant security risk and creates a significant attack surface.

  • Thank you for listening to your users. Persistent sessions bring a major usability improvement! (Especially for those users with strong passwords and 2FA enabled ;))

  • It’s great that you now have sub-folders. Are sub-labels on your roadmap as well? Gmail has offered sub-labels for years.

    • Hi Dean, at the moment sub-labels are not on the development plan, but I will share your request with the development team.

  • Please, we need the desktop application ProtonMail and the ProtonVPN in Flatpak. In the future for Proton Drive and Calendar.
    I’ve been waiting a long time for that to be able to opt for some payment plan, it’s not very nice (not for me) for relatives who are used to graphic interfaces to type commands into the terminal, it’s not very attractive, there are competitors who have cool applications.
    By the way, the new interface looks very good.
    Excellent work.

  • Great work, team!
    Just one thing noticed — subfolders work only on the web client. Desktop client, however, shows all folders and its subfolders on the same level.

  • Consider using ReasonReact in addition to React, to get more compile time type assurance of your codes safety and correctness.

    Also, consider adding mastodon and diaspora to your social sharing options on these blog posts.


  • New Beta site looks sleek and clean!

    Can you please add hover elements to the upgrade, settings and help icons at the top right of Protonmail Beta?

    • Hello Hervé,
      This is a good question. U2F makes two-factor authentication much easier, which reduces the burden on users and improves security. Now that we have a single domain for all Proton products, we are laying the groundwork to support U2F/FIDO2. Stay tuned to this blog and our social media channels for updates.

  • 2020-11-11

    Interesting. Does not work for my beta installation. I am required to sign on separately for each service (email / Contacts / Calendar) I had not read this blog post, so now I know exactly when I lost single sign on. It worked before the most recent update (I think.)

    Gmail does not have a problem on my computer (w10/firefox).

    Per my correspondence with the bug desk, I have given up the beta becaus

  • For what it’s worth, the single sign-on still doesn’t work with Firefox. logged in to mail, but still had to log in again to access contacts, and yet again to access calendar

  • This is of course great news, but I have to ask about the calendar features; specifically accessing the calendar via a mobile app, and syncing with desktop apps (eg lightening/Thunderbird), at least for paid users. For me, second only to email, this is one of the most important proton mail services… except I don’t use the calendar because its barely usable if I cant access it on my phone (effectively, via browser on my tiny mobile phone isn’t really a usable option for me) and sync it with my desktop/offline client.
    Regardless, I do appreciate the proton service, like the direction its going in and feel its worth the price… just wish the calendar was getting a bit more feature love.

    • Hi Johnny,
      We are currently working on Android and iOS apps for Proton Calendar. Thank you for your patience and support.

  • As a new user very concerned about Privacy it is special that I was directed to your program(s). As I review and use it the probability of becoming a paid user increases. Please keep up the great work.

  • hi,

    My words won`t express how happy I am reading about ProtonDrive. I was looking for something like that for a while now!
    Many of you probably don`t even realize how we are being tracked all the time. Well, I do… recently had an unreal story.
    Back to the point – it turned out how just singing up to google account which you need in case you have an android phone, etc. I got to privacy settings where I had to untick – permissions to save my history in google which wasn`t surprising but eg. device activity? When I used tinder? When I made a phone call to someone? When I opened my photos saved on my device? OR NOT TO RECORD SURROUNDING SOUNDS using my device/devices microphone and store it ??? Do I have to disagree with this???
    Plus the logs they keep – you once login using a certain device – they will find you when you use your credentials on any other device and associate you with it. Security is a joke. Plus no privacy at all!
    I love this – was attached to my crypto debit card from one of the US companies – “… We hope it also proves to be the first step for you take back the control of your money, data and identity. It`s after all a basic human right and only blockchain technology….”
    Privacy is our basic human right – and just belive me it`s violated every day – not only we have to accept recording everything in our surroundings to even use our mobile phone but how is it even legal?
    I am waiting so I can set up my phone using protonmail credentials bypassing google and store my photos, contacts, files and location safetly. To have some privacy. I think many people have been waiting for something you are doing. After reading this article I`ve upgraded as now tere is no question if its worth it. thanks for the great work

  • One major problem still remains. ProtonMail mobile version (Andoid in my case) still does not sync with the desktop version (this has been an issue since day 1). You can view emails on the desktop but the mobile app does not sync and reflect that the message has been opened/read, you still get new email notifications in the mobile version. Very annoying. This should be an “easy” fix I just don’t understand why it’s taking the team so long to fix this.

    • Hello Brian,
      We are currently working on syncing the mobile apps with the desktop. This should be fixed in the near future.

  • Where is the “session management” tool in the 4.0 beta settings?

    I thought this new version was about adding features, not subtracting them?…

    It’s an extremely poor decision to be removing highly useful features in exchange for useless ones that only cater to users that are too lazy to type a user name and password more then once ever.

    I could care less about persistent logins. I want to know where seassions are possibly still open.

    • Hi John. Go to Settings -> Overview -> Account settings – Manage Account (bottom of box on far right).