KeePassX is an open-source password safe for Linux, Windows and OS-X. Unlike the original KeePass program for Windows, which was also available as a Linux port, KeePassX is a complete rewrite. It’s advantage is that is does not rely on Mono.
Since KeePassX seems not really actively maintained, its fork KeePassXC is the recommended alternative to go for. It even introduces a new browser plugin called KeePassXC-Browser that integrates with Chrome/Chromium, Firefox and Vivaldi, providing improved security for the exchange of login data compared to its predecessor KeePassHTTP.
Storage location und backup
KeePassXC stores the entire database in one file with the extension *.kbdx at a location of your choice. This file should be backed up, for example to a thumbdrive or into the cloud. Since version 2, *.kbdx files are used. The previous version (*.kdb) may still be imported.
While KeePassXC remembers all stored passwords, one should not forget the master password to unlock the safe. Alternatively it is possible to use a certificate or authenticate with a JubiKey, allthough no real two factor authentification is possible.
Dokumentation for KeePassXC is available online. The quickstart instructions are not up to date as far as browser plugins are concerned, the FAQ does better. The Wiki is geared towards developers.
How to install KeePassXC
While KeePassXC is available from Ubuntu’s Universe repository, as a Snap or AppImage, the latest version is always available in the official Ubuntu PPA:
sudo add-apt-repository ppa:phoerious/keepassxc sudo apt-get update && sudo apt install keepassxc