View PDF files in Firefox

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  • Creator: AliceWyman
  • Comment: added warning for mac not to use the Adobe Acrobat plugin; other edits
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  • Reviewed by: ideato
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Firefox includes a built-in PDF viewer to display PDF files inside the browser window. This article explains how to use the built-in PDF viewer, how to use another PDF viewer and how to fix the common issues you might encounter.

Using the built-in PDF Viewer

Firefox includes a built-in PDF viewer that allows you to view almost all PDF files found on the web without a plugin. The built-in PDF viewer is enabled by default.

PDF JS

PDF Viewer toolbar functions

  • View document thumbnails or outline - The slider button on the far left will open a sidebar with thumbnails of the document's pages. Some documents will also have an outline view available. These make it easy to navigate through a long document.
    PDF Thumbnails
  • Page up and down or skip directly to a page - You can use the up and down arrows to page through a document or enter the number of the page you want to go to.
    PDF Pager
  • Change the size of the document - Use the + and - buttons to zoom in and out or choose a zoom setting from the dropdown menu.
    PDF Zoom
  • Fullscreen or Presentation mode - Click the fullscreen button to allow the PDF file to take over your entire screen. Press ESC to exit fullscreen mode.
    PDF Fullscreen
  • Print - Click the Printer button to open the print setup dialog.
    PDF Print
  • Download - Click the Download button to save the PDF file to your computer or to open it with a PDF reader program.
    PDF Download
  • Copy current view - Right-clickHold down the control key while you click the current view button to open the current view in another tab or window.
    PDF Copy

PDF Viewer keyboard shortcuts

Command Shortcut
Next page N or K or
Previous page P or J or
Zoom in Ctrl + +command + +
Zoom out Ctrl + -command + -
Automatic Zoom Ctrl + 0command + 0
Rotate the document clockwise R
Rotate counterclockwise Shift + R

Troubleshoot problems with the PDF viewer

  • With certain types of PDF files, the PDF Viewer may have problems displaying fonts, colors or the whole document. If some PDF files don't render well or are blank, click the download button on the right side of the document header to open it with the default PDF viewer application on your computer.

Using another PDF viewer

If you'd rather not use the built-in PDF Viewer, you can use a plugin to view PDF files in Firefox or you can view PDF files outside of Firefox using an external application. For more information, see How to disable the built-in PDF viewer and use another viewer.

To change from using the built-in PDF viewer to another PDF viewer:

  1. Click the menu button New Fx Menu Fx57Menu and choose Options.Preferences.
  2. Select the Applications panel.
  3. Find Portable Document Format (PDF) in the list and click on the entry to select it.
  4. Click on the drop-down arrow in the Action column for the above entry. The Action entry will show Preview in Firefox when you're using the built-in PDF Viewer.
    • To use a PDF viewer plugin, select Use PDF plugin name (in Firefox).
    • To use an external viewer, select the entry for the PDF application you wish to use, such as Use Preview or Use Adobe Reader.
Warning: You can use Adobe Reader as an external application but do not select the Adobe Acrobat plugin, since it doesn't work in Firefox. See PDF files are blank or cause an error message on Mac for details.

Using a PDF viewer plugin

Note: You will not be able to use a PDF plugin in the new 64-bit Firefox, which has limited plugin support. See How do I tell if I have the 32-bit or 64-bit Firefox?.

You can use a PDF plugin like Adobe Reader, Nitro PDF Reader or Sumatra PDF like Adobe Reader, MozPlugger, or KParts plugin, if one is available, to view PDF files in Firefox. If you have installed a PDF reader plugin but PDF files are not displayed in Firefox, try these solutions:

Enable the PDF plugin

Your PDF plugin may be disabled in Firefox. To enable it:

  1. Click the menu button Fx57menu , click Fx57Addons-icon Add-ons and select Plugins.
  2. Select your PDF plugin.
  3. Select Always Activate in its drop-down menu.

Reset download actions

  1. Open your profile folder:

    Click the menu button Fx57menu , click Help and select Troubleshooting Information.From the Help menu, choose Troubleshooting Information. The Troubleshooting Information tab will open.

    • Under the Application Basics section, click on Open FolderShow in FinderOpen Directory. A window will open that contains your profile folder.Your profile folder will open.
    Note: If you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.

  2. Click the menu button New Fx Menu and then click ExitQuit Close 29 .

    Click the Firefox menu Fx57Menu , then click Exit. Click the Firefox menu at the top of the screen, then click Quit Firefox.Click the Firefox menu Fx57Menu , then click Quit.

  3. Delete (or rename) the mimetypes.rdf file.

Other solutions

  • If the PDF plugin comes bundled with an application, check the application preferences, to see if there is an Internet setting to to enable the plugin or to display PDF files in the browser.