All ProtonMail apps are now open source, as Android joins the list!

An illustration of the ProtonMail Android app going open source.

Starting today, every app you use to access your ProtonMail inbox is open source and has passed an independent security audit.

One of our guiding principles is transparency. You deserve to know who we are, how our products can and cannot protect you, and how we keep your data private. We believe this level of transparency is the only way to earn the trust of our community.

To that end, open source has long been a priority at Proton. Our web app has been open source since 2015, our iOS app is open source, our desktop Bridge app is open source, and all ProtonVPN apps are open source.

This means that all Proton apps that are out of beta are open source.

Today we add the ProtonMail Android app to this list. The code is available on our GitHub page

As part of making our Android app open source, we commissioned an independent security audit from SEC Consult. Their audit found that our app has no outstanding vulnerabilities. We have also published the full audit report on our website. 

Open source at Proton

Your safety is our number one priority. Open sourcing our code increases the security of our apps because it allows us to leverage the entire IT security community to search for vulnerabilities. Those who discover vulnerabilities may be eligible for our bug bounty program

This means that the activists and journalists who rely on our service can be confident their communications will remain private.

Open source code contributes to a free Internet

Our goal is to bring security, privacy, and freedom to the Internet. That is why we are strong supporters of the open source community. We maintain two open source cryptographic libraries, OpenPGPjs and GopenPGP, to make it easier for developers to encrypt their apps and thus protect more data.

This cooperation among open source developers is how we create and sustain the privacy tech ecosystem that is necessary to create a safer Internet. Thank you to our community for supporting these efforts, and we look forward to your feedback on GitHub or directly via email at

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 or donate. 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

Richie Koch

Prior to joining Proton, Richie spent several years working on tech solutions in the developing world. He joined the Proton team to advance the rights of online privacy and freedom.

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24 comments on “All ProtonMail apps are now open source, as Android joins the list!

  • This is great news! Just a few more things to go in 2020 (Calendar and Drive) and it’s going be an awesome year for the ProtonMail users! :)

    • You are correct Ankush. We have a lot of big plans for this year. Keep an eye on this blog and on social media to make sure you keep up with our latest updates.

  • Thank you Proton for change actual World of backdoor and surveillance everywhere !

    The only way to be 100% sure about security is publishing all codes. You have found the right way for make money and let your code open.
    Everyone can check the code and it’s pretty hard to put backdoor inside open source code.

    • Thank you for your support Luc. You seem as excited about open source as we are. We’re happy to show our work and let everyone see exactly what our apps do.

  • Very happy to see this publication. I’ve been so satisfied with Proton these last years. Will Protonmail android app be on Fdroid app store soon? Is this something we could help with?

    • Thank you for you support. We have taken the initial steps to bring our Android app to F-Droid, but we still have some work to do before we can make our app available there.

  • Thanks a lot for making ProtonMail open-source, it adds a lot of transparency because we can now view the code and moreover under GPL license. I used ProtonMail only with its web version because I don’t have Google Play on my phone. So I’m looking forward to have the ProtonMail application available on F-Droid to be able to use it on my phone. ProtonVPN has already been added on F-Droid so why not with ProtonMail ?

    • Releasing ProtonMail on F-Droid requires significantly more development resources because of F-Droid requirements. We would like to do this, but we don’t currently have a timeline.

  • Dear Richie,
    What can be done to make it easier to use? I keep sending emails to myself erroneously. Gmail lay out is far better designed. Are there any improvements on the way?
    Best regards

  • Very nice!!
    Any plans to put Proton apps in open-source repositories, like f-droid, for people that are not into google?

  • Bought the paid plan for protonmail. Gmail is going to be all junk and protonmail is going to be all the serious stuff that matters. World needs more socially conscious technology. Moved into signal, brave, ecosia from whatsapp, chrome, google as well (even though ecosia is still using bing in the backend)

    I cannot wait to move completely away from Google and Facebook and all the monopolistic fiefdoms. Steam ahead proton team :)

  • I am also interested in getting ProtonMail from F-Droid. This allows me to keep ProtonMail up to date, without sacrificing privacy by installing the Google Play Store. Thank you!

  • I daily face the criticism by many in the online community that I am “paranoid” about the lack of privacy within the internet. For those who claim I must have something to hide I reply, “You do too!” Lack of privacy with email has always been a major complaint of mine and when I found ProtonMail I was elated!!!!! When security and privacy are considered paranoia you know you need it. I am new here on the free plan and I am slowly but surely getting happy with what I see. My paranoia is being satisfied and I’m looking ahead to soon upgrading my account(s) and also helping ProtonMail continue it’s mission. Thanks again, ProtonMail, for being as paranoid as me.

  • Thank you so much for what you do.
    As an American citizen I am now very worried about bigtech and its attack of the conservative family values I hold dear.
    I will be donating after sending this message!

  • If I download the new proton app through the Apple Store (which is tied to a gmail account), does that in any way reduce the privacy of using proton mail?

  • Hi and thanks for making privacy a priority!

    understand your security is based on encryption. I wonder if decentralized Blockchain technology would not be a better option to protect all our data and make sure that nobody can control it?