I know that there are extensive, "proper" methods for installing Firefox plugins. However, I would like to know where the folder is for linking shared-object (.so) files, such as libnpjp2.so and libflashplayer.so so that I can install plugins the "old-fashioned" way. In Firefox 21, I would have put it in ~/.mozilla/firefox/*[profile name].default/browser/plugins but that folder is no longer there. It keeps jumping around as Firefox changes. In about:plugins I still see all the plugins that I would have put there.

Can anyone tell me where the folder is? I already checked the folders in /usr/lib/firefox and /usr/lib/mozilla.

6 Answers 6


Please read the update at the end of this answer regarding changes in Firefox 52.

Acording to the Firefox developer documentation plugins live here:

  • Directory pointed to by MOZ_PLUGIN_PATH environment variable
  • ~/.mozilla/plugins
  • /usr/lib/mozilla/plugins (on non-Ubuntu 64-bit systems, /usr/lib64/mozilla/plugins might be used instead)
  • Plug-ins within toolkit bundles
  • [Profile directory]/plugins, where [Profile directory] is a user profile directory

Update for Firefox >=52

As of Firefox 52 support for NPAPI plugins has been dropped. All plugins living in one of the above directories are ignored, with the exception of Adobe Flash.

If you installed Flash with the flashplugin-installer package, it's loaded through a symlink in /usr/lib/mozilla/plugins that ultimately links to /usr/lib/flashplugin-installer/libflashplayer.so.

  • 12
    Mine is 64-bit system but i found out that it is at /usr/lib/mozilla/plugins. Also it is a good idea to have a look at about:plugins tab that may give a hint. Commented Jun 10, 2015 at 5:49
  • 2
    Fredrick Gauss's comment holds good for 14.04 too.
    – learner
    Commented Aug 9, 2015 at 3:38
  • @learner, thanks. The info is directly from the Firefox documentation. Ubuntu puts 64bit libs in /usr/lib and 32bit libs in /usr/lib32 instead of having a lib64 directory. So I changed the answer a little to reflect that.
    – mniess
    Commented Aug 11, 2015 at 13:31
  • 1
    @FredrickGauss Great suggestion about:plugins. This way I can instantly get exact plugin directory path and verify the update afterwards by just refreshing and seeing the 'state: UPDATE_AVAILABLE_<SOMETEXT> ' is gone. So Helpful. Commented Jan 10, 2017 at 5:42
  • As of Firefox 50 on Ubuntu 16.04.1, none of these directories is where the plugins are. about:plugins shows that Flash comes from /usr/lib/flashplugin-installer, but I couldn't find anything symlinking to that path. This answer suggests deleting pluginreg.dat. Commented Jan 23, 2017 at 4:57

I am on KDE 32bit 14.04 version. Firefox is already installed.

user Richard got negative reputation by telling us the correct path:


If you are proper linux user, it's no problem to move libflashplayer.so file to this directory as root user!

Youtube works after dat!

  • Can confirm Firefox >60 on Ubuntu-based >18.04 64-bits will also work with this. Commented Apr 13, 2019 at 13:40

Users should place plugins in /usr/lib/firefox-addons/plugins as root.

  • 7
    Users should do nothing as root.
    – mniess
    Commented Nov 29, 2013 at 23:02
  • 1
    This is only in the case you want a certain plugin to be automatically installed in all new user profiles. As a single user, you shouldn't install anything at all in this directory. Commented Nov 29, 2013 at 23:18
  • @darent Where should we install the plugin then? Commented Dec 22, 2014 at 10:15
  • @iamcreasy see the answer by user mnies
    – Richard
    Commented Dec 22, 2014 at 10:51

I found there is a directory /usr/lib/firefox/brower/plugins/.

My Ubuntu version is 16.04 LTS. How to enable flash player in Mozilla Firefox in Ubuntu is a helpful article. If there is not a directory named lib64, just copy the correct file to /usr/lib/firefox/browser/plugins/. Based on my experience, it also works well.


As a new Ubuntu user, I've been suggested to use the path mentioned by the about:plugins firefox command. In my case, it's pointing to /usr/lib/mozilla/plugins/.

Just mentioning here as I haven't seen this being mentioned. In case the approach isn't valid / reliable, I'd like to know why.

  • Umm.. The accepted answer mentions /usr/lib/mozilla/plugins, and the question itself mentions about:plugins.
    – muru
    Commented Dec 26, 2015 at 17:54
  • Yeah, my takeout is that, regardless of version, we should be using what's stated @ about:plugins (which was already known by OP, but - I believe - he wasn't sure if that path was the de facto path to be used or not). Commented Dec 26, 2015 at 18:05
  • OK.. You should cite the source where you got this suggestion.
    – muru
    Commented Dec 26, 2015 at 18:06

For flash player, using Ubuntu 16.04 64bit, /usr/lib/adobe-flashplugin/ is sufficient.

After downloading flash_player_npapi_linux.x86_64.tar.gz from Adobe website, I unpacked the archive and :

$ sudo cp libflashplayer.so /usr/lib/adobe-flashplugin/
$ sudo cp -r usr/* /usr

Restarted Firefox and done!

I can even see that /etc/alternatives/mozilla-flashplugin is a link to /usr/lib/adobe-flashplugin/libflashplayer.so

  • because the page about:plugins gave me the path /usr/lib/adobe-flashplugin for the shockwave flash plugin
    – anteldan
    Commented Mar 21, 2017 at 16:11

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