Enable Default Built-in PDF Viewer of Firefox

I never liked the idea of making some file format that requires its own reader for viewing whether it is the Word Doc or the PDF files. PDF files require Adobe PDF reader or any other PDF reader to open the file and can’t be opened without it. While it is not very difficult to install one, I would suggest if you could avoid the installation then why not?

For all those who have Chrome or Firefox browsers installed already on their system then there is perfectly no need to install any PDF reader. Chrome can be used to open a PDF file by default inside the browser and doesn’t require any specific reader for it, on the same lines, Firefox had also (with its new version FF15) released the built in Firefox viewer but it is disabled by default.

Here are some steps that can enable the default built-in Firefox viewer which can be used to open the PDF files. Doing this will also include a context menu “Open with” link on the PDF files so that you can open the files with firefox (thereby curbing the need of any PDF reader).


1. Open Firefox, on a blank tab enter the URL as about:config (this will open the configuration settings of the browser).
2. Click to confirm the warning message “I’ll be careful, I promise” to proceed further.

3. Now start searching “pdfjs.disabled” as shown to find it listed below. (if it is not present, then your browser is old and does not support it)

4. Right click on it to make the value False, as this will enable the PDF viewer. If the disabled value is False, then it means it won’t be disabled any more.

You might need to restart the Firefox once after which you will now be able to open any PDF file within the browser itself and don’t need any PDF reader even in the system. This way you can also get rid of the Adobe reader, if you don’t like it.

You can also get the add-on if you don’t like to do all this manually. The add-on can be found here.

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