Since the original article below was first published in 2014, we have made many improvements to how ProtonMail supports password managers. ProtonMail now supports three of the most popular password managers: LastPass, KeePass, and 1Password on both the webmail and our secure email mobile apps for iOS and Android.
To learn more about how to use these three password managers with ProtonMail, please visit the following article on ProtonMail Password Managers.
We highly recommend using a password manager as having a strong login and mailbox password is critical to securing your ProtonMail account.
Outdated post from August 2014 is copied below:
UPDATE: A fix has been put in place for LastPass. If you continue to experience problems, please let us know in the comments!
Many users have reported issues with ProtonMail and password managers such as LastPass. At the moment we are not fully compatible with these password managers due to the nature of our secure 2 password system. This post will outline why that’s the case and how we plan to help improve compatibility in the future.
Why it doesn’t work
ProtonMail uses 2 passwords to secure your account. The first password is used to authenticate you and log you into our system. The second password is only seen by you and is used to encrypt and decrypt your messages. This is a relatively new concept, and 99% of websites on the internet use just 1 password for logging in. Because of this, most password managers such as LastPass simply don’t work. In some cases, passwords are overridden by these password managers and in some cases these passwords are lost entirely.
The temporary solution is to not use password managers during our Beta. However, some of us at ProtonMail, myself included enjoy the convenience these password managers provide, especially the ability to generate long random passwords and save them for you. Because of this, it’s our goal to fix this issue if possible. We have a potential solution to fix this that involves some creative coding but it should do the trick and we hope to have this launched in the next 2 weeks.