I’ve just been playing around with https://browserleaks.com/fonts . It seems no web browser provides adequate protection for this method of fingerprinting – in both brave and librewolf the tool detects rather unique fonts that I have installed on my system, such as “IBM Plex” and “UD Digi Kyokasho” – almost certainly a unique fingerprint. Tor browser does slightly better as it does not divulge these “weird” fonts. However, it still reveals that the google Noto fonts are installed, which is by far not universal – on a different machine, where no Noto fonts are installed, the tool does not report them.

For extra context: I’ve tested under Linux with native tor browser and flatpak’d Brave and Librewolf.

What can we do to protect ourselves from this method of fingerprinting? And why are all of these privacy-focused browsers vulnerable to it? Is work being done to mitigate this?

  • Kairos
    3•4 months ago

    Does every Tor browser show the same fonts? That’s whats important.

    • @renzevOPEnglish
      2•4 months ago

      Okay, I just tested Tor on windows, and it shows a bunch of microsoft fonts that my linux box doesn’t have.

      But what I did notice is that the fingerprint changed on my linux box after a full restart of tor browser. So I guess their approach is to randomize fingerprints between sessions, rather then to keep everyone’s fingerprint the same?