[thebrain]

I tried enabling this recently and I immediately noticed that websites started appearing in light mode instead of copying my system settings and displaying in dark mode. It seems like in it's efforts to make my fingerprint the same as everyone else's Firefox stops telling websites about my display settings. The issue immediately went away when I changed the setting back to privacy.resistFingerprinting = false.

[pdonis]

Why does the browser need to tell the website about local display settings? In my case, with privacy.resistFingerprinting = true, the Zoom level resets to 100% every time I navigate to another page on a site. Why can't the browser just remember my zoom level locally and re-apply it? Why does it have to tell the website?

[hombre_fatal]

Zooming basically changes the dimensions of the viewport as JS/CSS see it. Reapplying the zoom level would involve running the same CSS media queries and/or JS so that the website looks good at those dimensions.

It's not just an "optical" zoom.

But more directly, zooming can put you in very nonstandard width x height dimensions. Carrying those dims across different pages makes for an easy fingerprint which is probably why it's reset.

[Spivak]

It doesn't have to but if you want websites to follow your system settings for light/dark mode then the browser has to tell the website which one you want at this moment.

[imran-iq]

To add on to this, why can't the browser just lie to the website but retain my local settings as is

[LikesPwsh]

That's intentional.

Uncommon settings being exposed to websites makes fingerprinting much more reliable.

[renewiltord]

That's how it works. The most common fingerprinting techniques use display settings, e.g. viewport size and this dark mode stuff

[mixmastamyk]

Dark mode is generally decided at the client via choosing which block of css to use. Are these sites sending different css instead?

[seanw444]

My primary issue is that it limits the refresh rate. It immediately gets choppier when scrolling, which is suuuuper annoying.