Firefox 15 Secret: Enable Hidden PDF Reader on Firefox Browser

By Sidharth | How-to

Did you know: You can read PDF files without downloading any addons or plugins on the new Firefox 15.

The above fact is slightly flawed though. Let me explain. Even if you have downloaded Firefox 15 on your computer, you won’t be able to read or view PDF files and documents because, for reason unknown, Mozilla decided to disable PDF reading by default.

This means you won’t be able to open PDF files as soon as you download the new Firefox browser. But the good news? We have a solution.

How to Enable Built-in PDF Viewer

You must enable the “PDF JavaScript.” By default, this element is disabled. Follow the instructions given below on how to enable it:

Step 1

Launch the Mozilla Firefox browser and type “about:config” (without quotes) in the address bar.

Address bar of Firefox 15

Step 2

You will receive a warning message. Go ahead and click “I’ll be careful, I promise!”

Warning message on Firefox 15

Step 3

Type “pdfjs.disabled” (without quotes) in the search box.

PDF File Reader on Firefox 15

Step 4

Double click on pdfjs.disabled. By double-clicking, we are changing the value from True to False (which means we are requesting to enable PDF reader).

Activating About Config on Firefox 15

Restart Firefox. Now you should be able to open any .PDF extension files right on your browser.

Using Firefox 15's PDF Viewer

About the Author

Hi, I am Sidharth. Full-time blogger. Editor of Blogote. And a self-proclaimed geek!