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How do I start Desktop Firefox in Offline Mode (if possible)?


Currently using Firefox 21* with 64-bit Windows 7 Pro SP1:

If I enable File > Work Offline, then Firefox will not retain the setting for the next launch. So it will always access the Internet (and complain if it can't) every time that it launches. There is no reason to do that, since security vulnerabilities in Firefox are ordinarily exploited only while it is accessing the Internet.

Although I am hesitant to edit about:config I can do that if I need to, but I don't know which line(s) I would need to change.

It would be best if I can launch Firefox with a command-line parameter to start with Work Offline. If so, I could launch it with a Windows shortcut which has that parameter in the Command field. However, Firefox command-line documentation ( https://developer.mozilla.org/en-US/docs/Mozilla/Command_Line_Options ) seems a bit outdated, and discloses that it is incomplete.

If memory serves, there used to be a way to do this, but I cannot recall the method.  :-(

Thank-you for your time and attention to this matter.

  • PLEASE DO NOT BOTHER TO TELL ME TO UPGRADE TO FIREFOX 22.!! As I have stated in other contexts, Firefox 22 requires me to spend far, far too much time and effort constantly "adjusting" the view and magnification of text and/or of images. IE 10 for Windows 7 has exactly the same problem and I returned to running MSIE 8. The Firefox workaround is a kludge that does not produce a satisfactory outcome. The assertion that we can continue using the Firefox 21 display by configuring that feature is either wrong, or the setting is broken. IT IS NOT A SOLUTION!! If the Mozilla developers refuse to allow us to *disable* this "improvement" and continue using the Firefox 21 display, then we will be looking for another browser that doesn't waste so much of our time just trying to get it to work right. THANK-YOU for respecting my point-of-view even if you cannot see it.

Additional System Details

Installed Plug-ins

  • Shockwave Flash 11.8 r800
  • Adobe Shockwave for Director Netscape plug-in, version
  • Next Generation Java Plug-in 10.25.2 for Mozilla browsers
  • NPRuntime Script Plug-in Library for Java(TM) Deploy
  • Google Update
  • 5.1.20513.0
  • GEPlugin
  • Foxit Reader Plug-In For Firefox and Netscape


  • User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:21.0) Gecko/20100101 Firefox/21.0

More Information

Helpful Reply

Update: I have found a command-line parameter which will do this:

(1) Create a Windows shortcut for firefox.exe. Right-click on the desktop, select New, then select Shortcut and Browse to the location of firefox.exe.

(2) Save the shortcut to the desktop. Then right-click on it, and select Properties.

(3) In the Target field, add -offline after the closing quotation mark and separate the parameter from the end of the string in quotes with a space.

Example: "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" -offline

When Firefox is launched with this shortcut, it displays a dialog to announce that it is offline and cannot access the Internet, and wants you to "Try Again". It would be nice if we could stop Firefox from displaying that dialog but I suppose that it will suffice to just close it.

Now if I can make that the *default* way to launch Firefox, that would be great!