How to Add Dark Mode in Sumatra PDF Reader

When it comes to opening PDF files on Windows or other platforms, Adobe Acrobat or Foxit PDF Reader comes to mind. But these popular PDF reader applications are becoming more and more demanding of the system resources with the release of every new update. As such, the people running relatively older computers are finding it increasingly difficult to open PDF files on their system. This is where Sumatra PDF Reader shines as new ray of hope. This PDF viewing application not only works on older version of Windows but it is also available in a portable application package.

Sumatra PDF Reader is one of the smallest, fastest and lightest PDF viewer application available today. Using this we can open any PDF file as it supports all the PDF format versions. It has all the basic features one would expect from a standard PDF reader application for Windows. However, it lacks the dark mode which is now being added to almost all the operating systems and applications.

We can add this dark mode easily in Sumatra PDF Viewer using the following steps:

  1. Launch Sumatra PDF Reader, click on its menu and select Settings and then Advanced Options.Add Dark Mode in Sumatra PDF Reader
  2. This will open SumatraPDF-settings.txt in Windows Notepad. This file stores all the settings for Sumatra PDF Reader. You can make a backup of this file because we are going to edit it.
  3. In this file find the values TextColor and BackgroundColor under the section FixedPageUI and change them to #F0F0F0 and #0F0F0F respectively. Save the file.Add Dark Mode in Sumatra PDF Reader
  4. Next time when you launch Sumatra PDF Viewer, it will open PDF files with dark background and the text would be light colored.Add Dark Mode in Sumatra PDF Reader

As you can see, it is not exactly the dark mode or dark theme available in other applications or browsers, but it does the job. We need a darker background in the dark mode and this is exactly what we get using these instructions. However, some PDF files may appear like photo film negatives in this mode. In that case, you can use the backup to revert to the older settings.