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An illustration of the Proton Mail Android app going open source.

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

Starting today, every app you use to access your Proton Mail 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(new window), how our products can and cannot protect you(new window), and how we keep your data private(new window). 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 (new window)since 2015, our iOS app is open source(new window), our desktop Bridge app is open source(new window), and all Proton VPN apps are open source(new window).

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

Today we add the Proton Mail Android app to this list. The code is available on our GitHub page(new window)

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

This means that the activists(new window) 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(new window) and GopenPGP(new window), 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 contact@proton.me.

You can get a free secure email account from Proton Mail here.

We also provide a free VPN service(new window) to protect your privacy.

Proton Mail and Proton VPN are funded by community contributions. If you would like to support our development efforts, you can upgrade to a paid plan(new window). Thank you for your support.


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

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