May 12, 2020 Download Open in PDF Reader for Firefox. Adds a context menu item to send PDF links directly to a PDF viewer like Adobe Acrobat Reader. FireFox comes with it's own PDF viewer, and you need to turn that off before Adobe Acrobat or Reader can take over and display the PDF files.

Many factors can affect the display of a PDF on the web, including damage to the PDF; how the website displays the PDF; the version of Acrobat, Reader, or the browser; security and cookie settings; or the status of the server on which the PDF resides. Try the suggestions below as your first troubleshooting steps.
If the Adobe Reader program is set as the default application for PDF files on your computer (right-click a saved PDF file in Windows Explorer and use Open or open with) then Firefox should offer this program as the first choice for an application when you get the Open with and save dialog.
If you want all PDF files to open in Adobe Reader only, click on Choose another app. In the pop-up that opens, select Adobe Reader and check the box next to Always use this app to open.pdf files. Adobe Reader and Adobe Acrobat integrate with Internet Explorer so that PDF files automatically open in the web browser by default. Fortunately, you can disable auto-open in Adobe Acrobat and Adobe Reader to prevent PDFs from opening in your browser.
Open PDF directly in Reader or Acrobat (quick fix)
If the PDF appears as a clickable link, you can often save the file to your desktop and open it directly. Downloading the file is a quick solution to get you going without further troubleshooting.
- Right-click (Windows) or Control-click (Mac OS) the link to the PDF file.
Choose the appropriate save or download option. The options vary depending on your browser:
- (Internet Explorer) Save Target As
- (Firefox) Save Link As
- (Safari) Download Linked File
Make sure Adobe Acrobat Document is selected for the file type, and save the file.
Note:
If you don't see a Save As dialog box, your browser could have opened a separate downloads window and downloaded the file automatically.
Locate the saved PDF, and double-click the file to open it. If your browser opened a downloads window, double-click the PDF in the downloads list.
Adobe releases regular security updates for Reader and Acrobat. It's likely that the latest update patch can fix a conflict with your system or browser.
Reader or Acrobat, or the resources they rely on, could have been damaged. Repairing the installation is a quick troubleshooting safeguard.
- (Reader) Choose Help > Repair Adobe Reader Installation.
- (Acrobat) Choose Help > Repair Acrobat Installation.
Viewing PDFs within a browser, requires that the Adobe PDF plug-in is enabled.

SeeTechNote Troubleshoot Safari Plug-in Problems | Acrobat X and Reader X.
The steps to enable the Adobe PDF plug-in vary depending on your version of Internet Explorer.
- Select Tools > Manage Add-ons. (Or choose Tools > Internet Options, click the Programs tab, then click Manage Add-ons.)
- In the Show pop-up menu, select All Add-ons. (In some versions the option is Add-ons That Have Been Used by Internet Explorer.)
Scroll to the section of add-ons for Adobe, and select Adobe PDF Reader.
- If the status of Adobe PDF Reader is set to Disabled, click the Enable button.
Adobe Reader For Firefox Download

- Click the Plug-ins tab (purple/blue icon). (The layout of this dialog box differs depending on the version.)
- Find and select Acrobat or Adobe Reader:
- If the Disable button is displayed (as shown above), the add-on is enabled and no action is required.
- If the Enable button is displayed, click Enable.
Firefox Adobe Reader
Note: Visit the Adobe Reader Help and Support page for assistance with other Reader top issues.