Why can't I open PDF files in a Firefox tab? Why do they open in PDF-XChange Editor instead?
Documents open in PDF-XChange Editor when I click on PDF links inside Firefox. I want to view documents in the browser. Why do they open in PDF-XChange Editor instead?
Firefox no longer offers support for NPAPI plugins, which means it is not possible to view PDFs in that browser as the relevant plugin for PDF-XChange Editor does not support it. Therefore, PDFs opening in PDF-XChange Editor is the correct setup.
Follow the steps below to determine the manner in which Firefox handles PDF files and other content:
1. Open Firefox and press F10 to enable the Menu Toolbar, then click Options in the Tools submenu:
The Preferences section will open.
2. Scroll down to the Applications section:
3. Use these settings to determine the manner in which Mozilla Firefox handles the listed content. The best setting for PDF files is to use PDF-XChange Editor.
N.b. If you wish you can set this to Preview in Firefox, however, this means PDF-XChange Editor and all of its features will be unavailable until you save the PDF-Document and open it directly within the PDF-XChange Editor.