Dark Mode for Sumatra PDF

Windows: version 10
Sumatra PDF: version 3.2 64-bit

A dark mode for Sumatra PDF is really easy – you just need to tinker with 3 lines of code in the settings.

Why Use Sumatra PDF?

In my opinion, it’s the best PDF reader. It’s small in size, super-fast and doesn’t have any annoying cruft.

Why a Dark Mode (Night Mode)?

If you code for long periods of time, then it’s really great to have your code editor run in dark mode. This greatly reduces the strain on the eyes.

But let’s say you are also following along an e-book, maybe a PDF and you switch to Sumatra PDF. The default setting is black text on white background. Immediately your eyes are shocked with bright luminescent white light. It’s as if you were relaxing in a room with the lights switched off and suddenly someone walked in and abruptly turned the lights on.

As you are coding along you have to switch back and forth multiple times between your PDF reader and code editor. It can be really jarring for the eyes and nerves.

How to Enable Dark Mode?

In Sumatra PDF, click on the Menu -> Settings -> Advanced Options

This should open the SumatraPDF-settings.txt file in your text editor. Change the following 3 lines under the heading FixedPageUI:

TextColor = #eeeeee
BackgroundColor = #111111
GradientColors = #000000

TextColor changes the text color of the PDF document. Background color changes, well the background color of the PDF document. GradientColors will change the background window of Sumatra PDF.

15 thoughts on “Dark Mode for Sumatra PDF

    1. Just tested on Sumatra PDF version 3.2 64-bit and works there also. However note that the upgrade will overwrite the SumatraPDF-settings.txt file. So you will need to modify the settings file again with the directives for the dark background.


  1. Hi there, thx for this article. I just downloaded Sumatra with Ninite, and the parameter `GradientColors` doesn’t exist in the `FixedPageUI` array. Even creating it exactly as your screenshot doesn’t work. I also tested with `GradientColor` instead, didn’t work either. Am I the only one who encountered this ?


    1. Hi kalak, thanks for your comment. It’s possible that the SumatraPDF version bundled with Ninite has a different configuration setting, though I can’t say for sure as I haven’t used Ninite before. Maybe try setting some other simple option via “Settings -> Advanced Options…” and see if it takes affect. If it doesn’t work then Ninite version of SumatraPDF is ignoring the default configuration file “SumatraPDF-settings.txt” and you might have to look elsewhere for the actual configuration file.
      However, I can confirm that the “Dark mode” for the stand-alone version works for sure as I have used it.


  2. Thanks a lot. I’m so glad I don’t have to use the garbage that Acrobat Reader is and have to suffer from the very high contrast bounding boxes around each citation and hyperlink that you can’t seem to disable/edit the color of and you can’t even manually remove them from the document unless you pay for the pro version. Seriously, fuck Adobe.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s