http://lpbitotptnhudy4llhyttmd2jynbuovpbyyz4nmt4zbozgtjr5pkomid.onion/privacy/keepassxc.html
At least 20 characters, but don't overdo it because you need to remember it and retype if every time you lock your computer / are inactive for a period of time; Enter multiple words separated by spaces; Never use phrases or expressions commonly used in speech, or any combination of words that can be found in articles or books; Don't use words that people knowing you associate with you, so avoid names of relatives and pets, hobbies, places that have a link...