I-Firefox Community Forum

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!

I closed a PDF file but can not move it to another folder. Windows says it is open in firefox. I closed firefox and it still says it is open in firefox. I even restarted windows and it still says it is open in firefox. How do I get firefox to close and release the file?

Certain PDFs only allow page view when opened in Firefox. When opened with other PDF viewing software or browsers (Microsoft Edge, Adobe Acrobat, Google Chrome), these PDFs allow continuous scrolling. I don't have this issue for most PDFs.

I've tried fixing the problem by editing the PDF settings in Adobe Acrobat but to no avail. When combining a PDF that works fine with a PDF that doesn't allow continuous scrolling in Firefox, it seems to take on the settings of not allowing continuous scrolling.

Examples (these link to documents from a Florida public document database): Example 1 (made with Power PDF Create) Example 2 (made with Adobe PDF Library): https://depedms.dep.state.fl.us:443/Oculus/servlet/shell?command=getEntity&[guid=5.506115.1]&[profile=Cleanup_Remediation]

Edit: Firefox 145.0.2, Windows 11

Hello,

Since the update I am unable to view pdf within xero and actionstep. These are important programs I require the viewing of the pdf for my employment. Can you let me know if there is a new setting that requires activation or if there has been a change. I have attached an image for you to see that it does not load.

Thank you

Tracy

Hello

I have found the IOS App permit now to Save PDF in a better way Thank you so much for this

I have found also the Link : https://support.mozilla.org/en-US/kb/save-web-pages-pdfs-firefox-ios

Is Showing a way to save the PDF but probably should be update now

Thanks for your help Loic Coupel

Recently, whenever I open saved (or sometimes new web) documents in Firefox, a very large pop-up on the lower right side of my screen appears with a cartoon of a pencil scanning a document. Below the cartoon it states "Now you can highlight your PDFs! With our new highlighter tool, you can read and edit PDFs in one place." The pop-up blocks half the view of the document and cannot be minimized or closed. It also prevents accessing (it hides) the "print" option if I want to print/save the page. I have WINDOWS 11 and have looked online for solutions to this problem which always produces the same suggestion: "go to 'settings', click 'privacy & security', check 'block pop-ups', click 'OK'", all of which I've done. I now limit my use of Firefox to streaming videos via amazon, and use Chrome or Edge for anything else I need to do, but I assume Firefox would not be happy to know of the aggravation their browser is causing, forcing users to go elsewhere (or am I the only person having this problem). Thank you in advance for any new suggestions.

I frequently use the firefox pdf viewer and greatly appreciate it. However when I use the highlight tool the large popup is distracting and covers up some of the contents on the page. Is it possible to have the tool selected and use it without having the popup being constantly open. See attached image

Trying to read PDF pages in Firefox. When I click on a file it says "You do not have OpenText Content Server Browser Web Extension 2.0.10 installed, or it is not enabled. Follow these instructions to install and enable the extension." I've looked in the extension add ons but cannot find the appropriate add-on and when I go to download from file, there are no files that would are appropriate either. Any suggestions? Also, I'm using a federal government laptop if that has anything to do with it.

Thanks guys for any help you can offer....

A msg box comes up that says go to setting to enable the ability to highligh pdf's. I went to settings and did not find. this box comes in the upper right hand corner. I am usually working in PAGES. jhelp if you can. Thank you.