How to change the internal pdf viewer in Mozilla Firefox
The latest version of Firefox launched yesterday and with it the long awaited internal pdf viewer that enables Firefox users to read pdf documents using the native client without the use of plugins. PDF.js, that's the name of Firefox's pdf reader, is a great addition not only functionality wise but also in terms of security.
While the new feature is certainly welcome by many users of the browser, it is likely that some users do not want to use the internal pdf viewer. The core reason here is certainly that another pdf reader is preferred for that task, another that some users noticed that the loading of pdf documents in the native viewer takes longer on their systems than plugins they used before.
Firefox is flexible enough to provide users with options to switch the default pdf viewer in the browser. There are two options available to do so:
- Change the default file handler for pdf files to another reader or download
- Deactivate the internal pdf reader so that another program or action is automatically selected.
Changing the default pdf file handler
To change the pdf file handler click on Firefox > Options to bring up the settings window. Here you need to switch to the applications tab where all file handlers are displayed.
Locate the Portable Document Format (PDF) content type there and look next to it to see the default action. If the internal pdf reader is used you should see Preview in Firefox here.
Click on the menu and change the action this way. You can switch to always ask, save file or use other which lets you pick a pdf reader installed on the system. Note that all installed pdf plugins are listed here automatically so that you can select them right away.
Deactivate the internal pdf reader
To deactivate Firefox's pdf reader you need to perform the following task:
- Type about:config into the address bar of the browser and tap on the enter key
- Confirm you will be careful if the warning message is displayed
- Type pdfjs.disabled in the search at the top
- Double-click the preference name to set its boolean value to true. This disables the internal pdf reader