Proton Mail

Proton Mail
Screenshot of the Proton Mail website, showing the conversation view of a message in a user's inbox
Available in
Headquarters
Plan-les-Ouates, Switzerland
OwnerProton AG
URL
  • proton.me/mail
  • protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion/mail
CommercialNo
RegistrationRequired
Users100 million (April 2023)
LaunchedMay 16, 2014 (2014-05-16)
Current statusOnline
Web Client
Written inTypeScript and Go
LicenseGNU GPLv3
Website
  • mail.proton.me
  • mail.protonmailrmez3lotccipshtkleegetolb73fuirgj7r4o4vfu7ozyd.onion
Repositorygithub.com/ProtonMail

Proton Mail is a Switzerland end-to-end encrypted email service launched in 2014. It is owned by the non-profit Proton Foundation through its subsidiary Proton AG, which also operates Proton VPN, Proton Drive, Proton Calendar, Proton Pass and Proton Wallet. Proton Mail uses client-side encryption to protect email content and user data before they are sent to Proton Mail servers, unlike other common email providers such as Gmail and Outlook.com.

Proton Mail received its initial funding through a crowdfunding campaign, and initial access was by invitation only, but it opened to the public in 2016. There were two million users by 2017, almost 70 million by 2022, and 100 million users in 2024.

The source code for the back end of Proton Mail remains closed-source, but Proton Mail released the source code for the web interface, iOS and Android apps, and the Proton Mail Bridge app under an open-source licence.