Assuming you have Acrobat 9.5.5 or above, this is how to enable using it in Firefox based on the experience of one of the firefox users:

a. INSIDE ACROBAT, set your preference for "Internet" to "view PDF files in browser." Close Acrobat. Close Firefox if it's already open.

b. Reopen Firefox. Check Tools/Add-Ons/Plugins to make sure the Acrobat plugin is there. Enable it if disabled. Close Firefox.

If the plugin isn't there at all, repair your Acrobat installation through Control Panel. Then return to Firefox and enable it. Close Firefox.

c. Reopen Firefox again. Go to Tools/Options and check the list of file types. For the names that contain "Adobe" and "Acrobat," Acrobat should be set as the default program to open them. Select it from the drop-down list if it's not. Continue to scroll through the alphabetical list--you should see another entry called Portable Document Format. If it's there, the default will be "preview in Firefox." You should be able to change this to "Acrobat (in Firefox)" using the drop-down menu. Do NOT pick the option that says "Acrobat"--this is the standalone program and will cause your PDFs to be downloaded.

If you don't see "Acrobat (in Firefox)" as an option, this means your plugin is not working. Go back and fix it using the instructions above (including repair of Acrobat if necessary).

d. If you don't see a file type for "Portable Document Format" at all, that means the Firefox PDF viewer is disabled. You must enable it by editing the about:config file. To see it, type about:config in the Firefox address bar. You will get a warning message--just click OK and keep going.

This file is a long list of statements in alphabetical order. LOOK FOR A STATEMENT THAT SAYS "pdfjs.disabled" with a Boolean value of "true." Select this statement and right-click. A context menu will offer you choices including "Toggle." Select that one, which will change the Boolean value to "false." Exit about:config. Close Firefox.

e. Now return to Tools/Options, scroll through the list of file types, and you should see "Portable Document Format." Select "Acrobat (in Firefox)" as in the instructions above. Close Firefox.

f. The first time you try to open a PDF file in Firefox, you may get a dialog box which offers you choices of how to open the file. The first will be Acrobat, but DON'T CHOOSE THAT--it will cause your PDF to download. Instead, go to the choice that says "Open as application/pdf." You don't need to change the program that opens this file type, because your settings are already correct. Your PDF should open in the browser, with the full-featured Acrobat menu (including the option of editing or saving the file).

Reference thread: https://support.mozilla.org/en-US/questions/950882 Any improvements?

How do I do (a) Inside Acrobat?

Hi John, actually could you clarify your question?

Firefox has a built-in PDF Viewer. That's actually the only option to view PDFs in a tab because Firefox does not run the Adobe Acrobat plugin (unlike Internet Explorer).

If you prefer Firefox to open PDFs directly into Adobe Reader instead of in a tab, could you check the steps in the following article: View PDF files in Firefox or choose another viewer (section titled "How to disable the built-in PDF viewer and use another viewer").

Hi raushani.me.rec, unfortunately the last version of Firefox that allowed the Acrobat plugin to run in a tab was the Extended Support Release of Firefox 52, so those old steps no longer work. See: Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?

Hi John, one other things. Let's say you are generally satisfied with Firefox's built-in viewer, but from time to time you prefer to open a PDF in Adobe. You can use the Download arrow button on the viewer's toolbar:

Hi jscher2000 I get the option in your screenshot and when I click on OK it doesn't open

jscher2000 said

Hi John, one other things. Let's say you are generally satisfied with Firefox's built-in viewer, but from time to time you prefer to open a PDF in Adobe. You can use the Download arrow button on the viewer's toolbar:

Hi jscher2000 I get the option in your screenshot and when I click on OK it doesn't open

Could you test in Firefox's Safe Mode? In its Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, any userChrome.css/userContent.css files, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Sorry I don't understand how to open in safe mode you are talking in another language

Sorry I don't understand how to open in safe mode you are talking in another language

Hi John, just keep reading with the next paragraph in that last reply, where the italics start.

https://support.mozilla.org/en-US/questions/1288711#answer-1316915

That is what I don't understand

Here are the steps:

If Firefox is not running: Hold down the Shift key when starting Firefox. (On Mac, hold down the option/alt key instead of the Shift key.)

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled
• (menu bar) Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

I told you I don't understand "3-bar" menu button > "?" Help button > Restart with Add-ons Disabled How do I get "3-bar" what do I do to get it? I am not an expert on computers I only know the basics. I am starting to get fed up as it is taking a while too solve

I call the main menu button at the right end of the main toolbar -- the one with a stack of 3 horizontal lines -- the "3-bar" menu button. When you click that, the Help item is near the button.

Am still unable to view documents as pdf in adobe reader in safe mode

Am still unable to view documents as pdf in adobe reader in safe mode

So the result is you get the PDF in Firefox's built-in viewer. When you click the Download button on the PDF Viewer's toolbar, it shows the Download dialog, but choosing Open, making sure the application is set to Adobe Reader, and clicking OK doesn't do anything in Safe Mode, either.

I don't know why your Firefox can't send the file to Adobe Reader that way. You could try the other workaround of setting Firefox to open ALL PDFs in Adobe Reader, or save the file and then open it in Adobe Reader.

I told you that I get that option in screenshot and when I click OK it doesn't open in normal mode and safe mode

Yes, that was my interpretation of your last reply.

I don't know why your Firefox can't send the file to Adobe Reader that way. You could try the other workaround of setting Firefox to open ALL PDFs in Adobe Reader, or save the file and then open it in Adobe Reader.

How do I set Firefox to open ALL PDFs in Adobe Reader and also save the file and open in Adobe Reader?

Hello John, To open all Pdf files on any browser in Adobe Reader, read through this article: https://adobe.ly/3gAeinH. Tell me if that helps and Stay Safe!

CAN YOU PLEASE READ EVERY QUESTION i ASKED AND EVERY ANSWER GIVEN AND THEN GIVE ME THE CORRECT ANSWER AS YOUR ANSWER DOESN'T HELP