When comparing KeePassX vs LessPass, the Slant community recommends KeePassX for most people. In the question“What are the easiest to use password managers?” KeePassX is ranked 9th while LessPass is ranked 10th.
Ranked in these QuestionsQuestion Ranking
Pros
Pro Free and open source
Pro Multi-platform
Run on Windows, Linux, Mac OS and Android.
Pro Open source
Pro Really platform-free
Works everywhere, in any device that can run javascript.
Pro Doesn't store passwords
If it's not stored, it can't be stolen.
Cons
Con Discontinued
KeePassX has been discontinued in 2017. KeePassXC is an open-source fork of KeepassX that is still actively developed.
Con No plugins / does not autofill login information
For example, the Keyorm plugin for the official Keepass client has the ability to open a website, and autofill username & passphrase info. This is an important and expected feature for a password manager, which is not available in KeePassX
Con Deterministic
Deterministic password managers have many drawbacks.
Con Cannot store existing secrets
Existing secrets (aka passwords) cannot be stored with deterministic password managers. In order to use LessPass effectively, you will need to change your password on every site.
Con Easily cracked with exposed/compromised master password
Since anyone can use LessPass with the same parameters as you, all they need is your master password (which could be obtained through keylogging or numerous other methods) to gain access to every one of your site passwords.