Mozilla’s latest version of Firefox – Firefox 19 is out with a modest set of features. The major change it sees is the incorporation of the most anticipated feature – built-in PDF viewer, PDF.js – which eliminates the need for third-party plugins – unless you prefer some for additional functionality.
The built-in or native PDF reader, as the name suggests, lets you only view the PDF documents. It cannot be used for filling out forms in PDF format. Also, it is a common notion, loading of pdf documents in the browser built-in PDF viewer takes longer than plugins, installed.
Thankfully, Firefox offers users with options to enable/disable the default pdf viewer in the browser. Here’s how you can disable or enable the built-in PDF Reader in Firefox 19 – and set another PDF Reader to open PDF documents.
Disable built-in Firefox PDF Reader
If you would like to disable or deactivate Firefox’s pdf reader, follow these steps:
Type about:config into the address bar of the browser and press the enter key. Next, hit ‘I Promise, I will be careful’ button if a warning message is displayed. Then, type pdfjs.disabled in the search at the top.
Now, double-click the preference name to set its boolean value to True. This will disable the internal pdf reader.
Change the built-in PDF Reader in Firefox
If you want to switch or change the default PDF Reader in Firefox, go to the Firefox Start page and click on ‘Settings’.
Next, choose ‘Applications’. Here, you will see an option ‘PDF’ in ‘Content type’ and ‘Preview in Firefox’ action corresponding to that content type. Preview in Firefox option indicates that the built-in PDF viewer is enabled.
When you download a file in the PDF format, you will be asked to open the file with the default PDF program, already set on the computer. You will get this option as the the first one, immediately after you click a PDF file.
Please note that when you open a PDF file in the built-in PDF viewer, you may get a warning message on your computer screen reading as – ‘This PDF document might not be displaying properly’. You can switch to a different viewer, if you want. ‘Other’ option will let you pick a pdf reader of your choice or the one installed on your system. All installed pdf plugins can be found listed here so as to make it easier to switch to them right away.
Hope that helps!
How to Disable built-in PDF Viewer in Chrome may also interest some of you.