Every time I manually touched the "fingerprinting" about:config settings, my entropy went up. I used the EFF site to test: https://coveryourtracks.eff.org/
AFAIK some of these options are there to be used by the Tor browser, which comes with strict configuration assumptions, and it doesn't translate well to normal Firefox usage. Especially if you change the window size on a non-standardized device. Mind you, the goal is not to block fingerprinting, but to not stand out. Safari on a macbook is probably harder to fingerprint than Firefox on your soldering iron.
However, judging by the fact that every data hungry website seemingly has a huge problem with VPN usage, I'd presume they are pretty effective and fingerprinting is not.
I've had good success with tracking tool tests and resistFingerprinting. Granted, I usually use it with uMatrix/NoScript most of the time which cuts down on the available data a lot and maybe makes it an unfair test.
One issue, I expect, is simply not enough people using resist fingerprinting to add variation to the mix. Since it's off by default, and only a small % of users use Firefox and an even tinier percentage use resistFingerprinting, unlike your example of Tor where probably most people on the tor network use the tor browser, it's likely that simply blocking things is a fingerprint all on its own.
The solution there would be to get more people using it :)
I will say one downside to using it is far more bot detection websites freaking out over generic information being returned to them, causing some sites to break (some of their settings breaking webgl games too due to low values). Using a different profile avoids this, or explicitly whitelisting certain sites in privacy.resistFingerprinting.exemptedDomains - obviously if a site is using a generic tracking service for bot detection, that kills a fair amount of the benefit of the flag, so a separate profile might be best. I wish firefox had a container option for this.
... and. not too sure what you mean by changing window size on a non-standardised device. They do try to ensure the window sizes are at standard intervals, as if they were fullscreened at typical widths to reduce fingerprinting, but surely that applies to using Tor too? I mean, people don't use Tor on dedicated monitors at standard sizes.
Oh, and a bit of followup. I tried the EFF cover your tracks on a Firefox profile with resist fingerprinting, and almost all the bits of identifying information came from the window size (which EFF considers "brittle") and the UA (I was testing in Firefox Nightly).
Apparently you need to add the hidden pref:
firefox.resistFingerprinting.letterboxing
Enabling letterboxing knocked off 5 bits of identifying information. Apparently my 1800px wide letterbox was still pretty identifiable, but, an improvement.
Setting a chrome user agent string using a user agent string manager dropped that one from 12ish bits to <4 bits. 'course, that has disadvantage of reducing firefox visibility online further, and probably being more recognisable with the other values (like mozilla in the webgl info). Using firefox stable for windows was <5bits, so probably best to use that if on linux. Although, it might conflict with the font list unless a windows font list was pulled in.
privacy.resistFingerprinting has potentially-unwanted side-effects, like wiping out most of your browser history (instead of the more sensible approach of just disabling purple links). I also recall something about it getting removed or nerfed, though I'm not sure whether that was a mere proposal.
It does not wipe your browser history. I can definitely attest to that since my generic JS active + resistFingerprinting profile has a history going back years. It does set your timezone to UTC in JS on websites. I've mostly encountered that when playing Wordle ;)
The browser should reasonably know what time zone you're in and what time zone you're reporting to the website and translate between them automatically.
Yeah, "should". Too bad it's unfeasible. As soon as you e.g. print the current date as part of a paragraph somewhere, the browser loses track of it, and the website can just read the element's content and parse it back.
what about duck duck go? We need a simple chart:
1. What browsers are good at resisting finger printing
2. tell for each browser, does it work on android ad ios and apple and windows and linux
3. what setting are needed to achieve this
for bonus points, is there no way to strip all headers on chrome on control it better?
Modern Safari is pretty damned good at randomizing fingerprints with Intelligent Tracking Prevention. With IOS 26 and MacOS 26, it's enabled in both private and non private browser windows (used to be only in private mode).
All "fingerprint" tests I've run have returned good results.
