Why do you need JavaScript, sessionStorage, and cookies?
For security reasons, Proton Mail and Proton VPN require JavaScript, sessionStorage, and cookies. Not having any of these enabled may cause errors. This article describes how to fix these errors.
In order to perform encryption and decryption in your web browser and to properly authenticate you, we need to use JavaScript for the encryption and decryption process.
We also use sessionStorage to save your private key(s) locally.
Finally, Proton Mail and Proton VPN require cookies to be enabled so that we can store your current session information and log you into your account.
Learn how to enable JavaScript(new window)