FireFox PDF Reader

There are several excellent free PDF readers, such as Adobe Reader and Nitro Reader, but you still need to download and install the big program, just for viewing one PDF file sometimes, here we would like to recommend the built-in Firefox  PDF Reader, you can view PDF files in Firefox without installing any other PDF Reader. Although it doesn’t have more features than Adobe PDF Reader, but it is enough for common PDF reading and OSX edit DF.


Before you start using Firefox’s PDF reader, please make sure you have the latest version of Firefox, and the Adobe PDF View plug-in in Firefox has been disabled. The version information can be checked under Help > About menu. To disable the Adobe plug-in, select Add-ons, click on Plug-ins and then click the Disable button next to Adobe Acrobat. The last step is to enable Firefox PDF viewer.


  1. Open Firefox and enter “about: config” in the address bar,
  2. Search for browser.preferences.inContent near the about:config area.
  3. Search for pdfjs.disabled, then right click and toggle this setting.

After these three steps have been done, you could view PDF in Firefox freely. Other PDF tools also install plug-ins in browsers, but it may slow the opening speed of the browser and is not easy to uninstall completely. Based on the steps mentioned above, it is still not convenient for users to activate the settings, hope it will be simplified and more friendly.