Is there any way of getting a unique device id, that are consistent with nodejs/express/some npm module? I've tried with fingerprintjs2 on the clientside, but that isn't consistent, meaning I can get two different id's based on where I'm at.
It also needs to be without any use of saving cookies on the clientside, and has to be "calculated" with the same outcome everytime for each unique browser/user/whathaveyounot. The outcome has to be unique for each browser, somewhat similar to android-id in android.
EDIT: Im wondering this to try and create a login-free "service" that rely on the users device-id as login/username, releaving the user of all registration and whatnot
There is no way to identify an instance of a browser on the internet reliably. There are a multitude of reasons why we all use sign in systems, security and user validation is not an easy problem to solve.
If you want to ease the experience for the users look into using OpenID, your users will be able to log in using their existing google or facebook etc accounts fast and easy.