To easy understand what i am saying, i will give you this example, you visit domain.com but on this page there are other things from external domains other than domain.com that firefox fetches/connects to - cdn.blabla.com; third-party.socialwebsites.com, etc. What i want, is to simply not connect to any other domain except what i typed in url bar. I understand it can break pages but i dont care.
A while ago, setting permission.default.images to 2 somehow worked and stopped loading of external content. Disabling prefetch/preconnect/predict/predictor does nothing.
p.s. i dont want to use extensions, only about config.
i hoped there are some config values that i am unaware of to do the changes i want.
open source = some parts of the code can be open at best, it isnt what it sound. license matters. this word is just a trick.
yet, i wouldnt count on someone auditing code, there was lots of big projects with trully open code that had bad code injected for decades and noone noticed.
as much as i know, those extensions call back on developer server for updates/new filters etc. so i skip.
You don’t have to update the filter lists. You can have a totally local offline list that never updates, but you can add your own exceptions and filters. I mean you can do what you want, but I think there are some misconceptions. In example uMatrix is not spyware. It does not send unwanted information to developers back. And people audit not only the code, but also what is sent through network after installation.
If you really don’t trust much, which is understandable (i am not trying to convince you to install spyware), then I think Firefox is not the best browser for you. In that case it would be better to use a browser like LibreWolf, a fork of Firefox with configurations of privacy and security in mind. It comes with uBlock Origin plugin though, if that is a deal breaker.
Good luck finding a solution. I don’t know any way doing it in Firefox without addons.