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Firefox built-in PDF viewer stuck in light mode when privacy.resistFingerprinting is enabled

  • 1 përgjigje
  • 0 e kanë hasur këtë problem
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  • Përgjigjja më e re nga Paul
  • Arkivuar

Hi everyone,

After enabling `privacy.resistFingerprinting = true` in `about:config`, I noticed that Firefox’s built-in PDF viewer (`pdf.js`) is always displayed in **light mode**, even though my system and browser themes are both dark.

I understand that RFP forces `prefers-color-scheme: light` to prevent fingerprinting, but this also affects internal components like the PDF reader. Unfortunately, the PDF viewer doesn’t provide a manual dark mode toggle.

Is there any **official or safe workaround** that allows keeping RFP enabled while still having the PDF viewer use dark colors?

Thanks!

Hi everyone, After enabling `privacy.resistFingerprinting = true` in `about:config`, I noticed that Firefox’s built-in PDF viewer (`pdf.js`) is always displayed in **light mode**, even though my system and browser themes are both dark. I understand that RFP forces `prefers-color-scheme: light` to prevent fingerprinting, but this also affects internal components like the PDF reader. Unfortunately, the PDF viewer doesn’t provide a manual dark mode toggle. Is there any **official or safe workaround** that allows keeping RFP enabled while still having the PDF viewer use dark colors? Thanks!

Krejt Përgjigjet (1)

Hi

The fingerprinting resistance is based on presets to try to achieve that aim and may not always lead to a configuration you would prefer for browsing.

An overview of a number of the settings are at https://support.mozilla.org/en-US/kb/resist-fingerprinting and I would avoid about:config if possible.