Today I switched ON the "Responsive Design Mode" under the "Web Developer" Section of the Firefox menu, and from the dropdown menu selected "iPhone X/XS iOS 12".

So now every webpage I visited was being sent the request that the screen size of my device was "375x812".

My question is that, can this method enhance my protection against browser fingerprinting(assuming I also take some other precautions)? Because the websites now wouldn't be able to know my original aspect ratio/screen resolution, and above 2 iPhones are quite common too(I am using a laptop).

I earlier tried to scale the Firefox window to nearly the aspect ratio of a mobile phone, but that didn't make any differnce at all.


(i) In the context of this question my adversaries are only the companies and their websites,and not the Governments & ISPs.

(ii) I am just asking about the effect of this method on my browser's fingerprint, that is, whether it will increase or decrease the uniqueness of my fingerprint. Be advised: I am not using this as the only method.

(iii) Firefox version: 78.0.2

(iv) OS: some linux distro.

1 Answer 1


There is no single fingerprinting method. But assuming that the fingerprinting you fear tries to be as granular as possible it will not only include easily fakeable things like User-Agent header but will also include things like font rendering, canvas performance etc - see here for some extensive but still incomplete and somewhat outdated list of ways to identify a client.

In this case a system with the performance of a desktop, Linux specific font rendering but a reported screen size of an iPhone will likely stand out as even more unique than if the browser would have reported the real screen size.

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