Enable In-built PDF Support in Mozilla Firefox

After Google Chrome started out with an in-built support for viewing PDF files, there was pressure on other web browsers to support PDF files too. As a result now Mozilla Firefox has also created in-built PDF support starting with the version 15 of the browser. Using this feature, you can view PDF files right inside the Firefox browser without having to need any third party software like Adobe Acrobat or Foxit Reader. By default, this in-built PDF support is not enabled in Firefox. But you can enable it using few simple steps.

Enable In-built PDF Support in Mozilla Firefox

To enable the in-built PDF viewer in Firefox browser, you can follow these simple steps :

  1. Open Mozilla Firefox browser. In the location bar type about:config and press Enter.
  2. Firefox will show a warning. Click on the button labeled I’ll be careful I promise! to proceed.

    Enable In-built PDF Support in Mozilla Firefox

  3. In the Filter field type pdfjs. You would see a preference named pdfjs.disabled as shown.

    Enable In-built PDF Support in Mozilla Firefox

  4. Double click on pdfjs.disabled to change its value to false.
  5. After changing the value, restart the browser for the changes to take effect.

After enabling the in-built PDF support in Firefox, when you click on a PDF file link, it would be automatically opened in the in-built PDF viewer. You can also drag & drop a PDF file in the Firefox window to open it in the Firefox PDF viewer.