All ProtonMail apps are now open source

ProtonMail has open sourced its Android app, meaning all ProtonMail and ProtonVPN apps are now open source.Open sourcing allows anyone to review the code and verify Proton's data protection claims are accurate.The company also announced that all ProtonMail and ProtonVPN apps have also passed an independent third-party security audit.

ProtonMail has published the code for all its apps following the open sourcing of the ProtonMail Android app. The company said, "Transparency is one of Proton's guiding principles, which is why it's always clear who runs the organization, what its data policy is and the capabilities and limitations of the technology".

By open sourcing all the apps, Proton is allowing users the same level of transparency into its code. Any security researcher can now verify if Proton is handling user data in the way that it claims. This extra layer of transparency means that everyone, including activists, dissidents and journalists who rely on Proton's service can check if their communications are as private as promised.

Open sourcing code also increases security for apps as it allows the entire IT security community to search for vulnerabilities. Proton also runs a bug bounty program, allowing the community to report bugs and vulnerabilities.

The ProtonMail Android app was audited by SEC Consult. The audit report has been published on the ProtonMail website.