If you use Mozilla Firefox as your browser, you’ll probably find that your PDF files have been looking a little different recently. This is due to the latest Firefox update. Here we explain what you can do about it.

To the rescue – deactivate pdf.js

To get everything working again as it should, a few steps are needed. This means replacing the new internal PDF pdf.js viewer with the Adobe plugin (Windows) or Preview (Mac OS). Here’s how:

Windows

  1. Open Firefox
  2. Go to the Extras > Settings menu
  3. Then click on Applications
  4. In the list in the left hand column look for the file type Portable Document Format (PDF)
  5. In the right hand column Preview in Firefox select the Use Adobe Acrobat (in Firefox)option

Mac OS

  1. Open Firefox
  2. Click on the menu item Firefox > Preferences
  3. Then click on Applications
  4. In the list in the left hand column look for the file type Portable Document Format (PDF)
  5. In the right hand column Preview in Firefox select the Use Preview (Standard) option

Now Firefox 19 will once again show the PDFs in Adobe Acrobat Reader / in Preview rather than in the broken internal viewer.