View and edit PDF files using Firefox’s built-in viewer

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  • Revision id: 15585
  • Created:
  • Creator: scoobidiver
  • Comment: removed ref. to Adobe Reader on Mac, reworded last sentence in each section
  • Reviewed: Yes
  • Reviewed:
  • Reviewed by: mluna
  • Is approved? Yes
  • Is current revision? No
  • Ready for localization: No
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A PDF reader plugin can be used to display PDF file inside the Firefox browser window. If there is a problem with the plugin, Firefox may try to download the PDF file instead of opening it. This article helps you to open PDF files within Firefox.

Some PDF readers plugin are:

Only the first page is visible (Mac 10.5 and below)

If PDF documents open within Firefox but only the first page is viewable, make sure that the QuickTime plugin isn't set to handle PDF content:

  1. From the Apple menu, choose System Preferences.
  2. From the View menu, choose QuickTime.
  3. Click the Plug-In tab and click MIME settings....
  4. In the list of MIME types, click the triangle next to "Images - Still image files".
  5. If "PDF Image" is checked, click the check box to clear it.
  6. Click OK

If you can't view a PDF in Firefox, continue with the next following instructions.

Check Firefox settings

  1. In the Menu bar at the top of the screen, click Firefox and select Settings (select Preferences on older macOS versions).Click the menu button Fx89menuButton and select Settings.
  2. Select the Applications panel.
  3. Find Adobe Acrobat Document (if you're using Adobe Reader) or PDF files (for other PDF readers) in the list and click on it to select it.
  4. Click on the drop-down arrow in the Action column for the above entry and select Use PDF reader name (in Firefox).
    Opening PDF - Win

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    • If Use PDF reader name (in Firefox) is not listed as an Option, see Reset download actions below and then repeat this set of instructions.
  5. Close the Settings page. Any changes you've made will automatically be saved.

If you still can't view a PDF in Firefox, continue with the following instructions.

Reset download actions

  1. Open your profile folder:

    • Click the menu button Fx89menuButton, click Help and select More Troubleshooting Information.From the Help menu, select More Troubleshooting Information. The Troubleshooting Information tab will open.
    • Under the Application Basics section next to Profile FolderProfile Directory, click Open FolderShow in FinderOpen Directory. A window will open that contains your profile folder.Your profile folder will open.Your profile directory will open.
    Note: If Firefox displays an error after clicking Open Folder or if you are unable to open or use Firefox, follow the instructions in Finding your profile without opening Firefox.

  2. Click the Firefox menu Fx89menuButton and select Exit.Click the Firefox menu at the top of the screen and select Quit Firefox.Click the Firefox menu Fx89menuButton and select Quit.
  3. Delete the mimetypes.rdf file.


Check Application settings

If the PDF reader plugin comes bundled with a reader application, check the application plugin setting if there is some.

  • Adobe Reader:
    1. Open Adobe Reader.
    2. Once in Adobe Reader, click the Edit menu in the menu bar, and then click Preferences... The Preferences window will open.
    3. In the Categories section, click on Internet.
    4. Make sure the first check box, Display PDF in browser, is checked.
    5. Click OK to dismiss the Preferences window, and then close Adobe Reader.

If you still can't view a PDF in Firefox, continue with the next following instructions.


Re-initialize the plugins database

Follow the instructions in the Re-initializing the plugins database section of the Troubleshoot issues with plugins like Flash or Java to fix common Firefox problems article.

This will force Firefox to rebuild its plugin database. If you still can't view a PDF in Firefox, continue with the next following instructions.


Re-install the application

If the PDF reader plugin comes bundled with a reader application and the above troubleshooting methods for Firefox did not work, uninstall and re-install the application.

If you still can't view a PDF in Firefox, continue with the next following instructions.


Further information for Adobe Reader

If none of the above troubleshooting methods worked, see Can't view PDF on the web from Adobe.com for further instructions.