Dark mode for Embedded pdf Viewer

[dpa]

Hello everyone...

I use Firefox a lot of years and i am very happy with the interface.

But i saw that there is no built-in option to change  the Mode of Embedded PDF Viewer in to Dark

Is possible to be implemented in the near Future...?

Thanks in advanced.

[Agentvirtuel]

Hello

If you'd like to try (and see) ui.systemUsesDarkTheme

Configuration Editor for Firefox
https://support.mozilla.org/en-US/kb/about-config-editor-firefox#w_adding-preferences
Adding preferences ui.systemUsesDarkTheme Number value 1

https://www.youtube.com/embed/JTkwNDFEViM

[Toni]

@Agentvirtuel 

Thanks, but that does not change pdf to black background.

[ETL]

@jscher2000 After Firefox v121 the pdfjs.viewerCssTheme pref does not work when resistFingerprinting is enabled.

[buhbuhbob]

PDF viewing has an "invert colours" option

It would be nice to be able to invert the colours of PDFs, to be able to read white text on black backgrounds. Firefox extensions that invert colours are blocked on PDF viewing.

[Jon]

(Note: similar ideas have been merged into this thread)

[mozzer]

Bookmarklet to force Dark Mode for Firefox PDF view

Add two scripted bookmarks, e.g. via Bookmark Manager in the URL field.

Name: force PDF Dark Mode
Url:

javascript:(()=>{window.PDFViewerApplication.pdfViewer.container.style.filter = "invert(85%) grayscale(0)" })();

Name: remove overrides; show PDF's styles
Url:

javascript:(()=>{window.PDFViewerApplication.pdfViewer.container.style.filter = "" })();

The advantages (if you like them):

• Apply on a per-window basis, so you only restyle documents that need it
• Sync bookmarks to multiple machines
• Forget machine-specific folder digging
• No Firefox restart required

Thanks to @Ethab83 for the script. I modified to use 85% contrast and to make it a button-click instead of opening the dev console.

[Agentvirtuel]

Hello

Of course, this is not the expected answer, however, this possibility to come.
https://connect.mozilla.org/t5/ideas/black-background-for-reader-view/idc-p/56833#M33280

[shivaprasad]

doqment PDF Reader: Firefox's PDF viewer with reader mode

I created a PDF reader extension, building on top of the embedded viewer, that can display PDFs in different light and dark themes, just like @ArkitectNaut said in their comment. This might be the solution you are looking for. Please try it out!

https://addons.mozilla.org/en-US/firefox/addon/doqment/

Bonus point: it is available also for Android!

PDF in Firefox dark themePDF in Firefox light theme

[alexfromapex]

I tried to create an add-on for this but it's not able to run on the PDF viewer pages, so for now the bookmark looks like the only option

[ostman]

really good idea. i am waiting for it

[wolfmaster010]

I just updated Firefox to 132.0. It removed the user CSS fix for styling a page, so now toolkit.legacyUserProfileCustomizations.stylesheets and Usercontent.css no longer work.

Instead, the changelog notes "The -moz-user-modify  CSS property has been removed. This property has been deprecated in favour of the contenteditable  global attribute." Anyone know how to use contenteditable to get the same result??

[wolfmaster010]

Firefox just removed the CSS solution for contenteditable. I think this removed the functionality of both toolkit . legacyUserProfileCustomizations . stylesheets option and userContent . css.

"The -moz-user-modify CSS property has been removed. This property has been deprecated in favour of the contenteditable global attribute."

Anyone know how to set up the new contenteditable?

[jscher2000]

Hi wolfmaster010, as far as I can tell, both the toolkit.legacyUserProfileCustomizations.stylesheets preference and the option to use a userContent.css file are still present in Firefox.

contenteditable is an attribute, not a style property, so you cannot apply contenteditable using CSS. See: https://developer.mozilla.org/docs/Web/HTML/Global_attributes/contenteditable

If you are asking about this for a different reason than applying a dark mode to the built-in PDF viewer, I suggest starting a new discussion over here: https://connect.mozilla.org/t5/discussions/bd-p/discussions