I've set Firefox to always ask me whether to activate a plugin when a site uses them. Normally, I will see a grey box on the page where the plugin is used, in which I can click to activate it.

For some pages, however, Firefox displays a large bar at the top asking me whether to active the plugin, see the image below. I assume this is because the flash or applet is not actually visible on the page, but it used to just be a small, brief message in the address bar, instead of a big, intrusive bar I have to manually close down. And it's unnecessary too, since I can just click on the plugin icon next to the address (also seen in the image) if I wanted to activate these hidden plugins.

How do I stop this bar from appearing? I've searched all over Google, and under about:config too, but found no answer.

The bar in question

  • Are you running Ubuntu? What Firefox version are you using?
    – and31415
    Feb 12, 2014 at 14:28
  • @and31415 Yes, and 27
    – user299493
    Feb 12, 2014 at 14:33
  • Great question. I really wish Mozilla would stop ruining their UI. Nov 29, 2014 at 17:30

4 Answers 4



I was annoyed too by the notification since it was introduced. There's no user setting which can control it, and probably there never will be. Disabling click-to-play wasn't an option for me, so I looked for possible solutions.

The manual way

I'm listing this first as it's the most efficient way.

  1. Close Firefox.

  2. Add the following code to your userChrome.css file:

        display: none !important;

    It is located in the chrome subfolder inside your Firefox profile folder. Create one in case it doesn't exists already. Here's an example: userChrome-example.css.

    Note As reported by @Smylers, !important doesn't seem to be needed and could be omitted.

  3. Start Firefox again.


If you have the Stylish add-on installed, you can get the Notification bar for 'hidden plugin' - disable style:

This style hide notification bar (infobar) for hidden plugin activations - eg. hidden frame or non-visible div.

Using an add-on

Install the Hide Plugin Notifications add-on:

Hides the hidden-plugin information bar in Firefox.

It basically injects the custom CSS code every time you visit a website. No restart required.


  • 1
    Beautiful, the manual way works like a charm. Thanks
    – user299493
    Feb 12, 2014 at 16:02
  • I'd really like to give you zillions of +1.
    – metadings
    Aug 5, 2014 at 11:23
  • You're a life-saver. I can't believe how many sites use hidden Flash trackers. Nov 29, 2014 at 17:29
  • Sadly the add-on no longer works, but the userChrome.css still does.
    – RomanSt
    Aug 14, 2015 at 14:46

There is also a Firefox addon:

Hide Plugin Notifications:

"Firefox will now show an information bar for every site that uses a hidden plugin, to aid discoverability for users. This addon will let you turn off that infobar, if you know about the icon in the location bar. This is especially helpful if you have Flash marked as click-to-play."

It works like a charme!


This comes from the Firefox Click To Run feature whereby plugins can be set to require activation by the user each time they are encountered.

Recent versions of Firefox have marked some plugins Click To Run by default. This is due to a perceived security risk with the plugin. This includes certain versions of Flash and Java.

To change the settings, go to Tools -> Add-ons then select the Plugins tab. Each of your existing plugins will be listed, along with a drop-down menu from which you can select Always Activate if you so wish.

  • 2
    The settings I use for plugins are intentional. I'd like to keep them deactivated by default but get rid of the message. It is unnecessary and intrusive
    – user299493
    Feb 12, 2014 at 13:12
  • Answers like this are typically who these banners are aimed at... users who don't mind things pushed down their throat
    – Precastic
    Dec 1, 2014 at 8:18

How do I stop this bar from appearing?

You can use an unofficial style sheet hack. There are also addons that inject those style sheet modifications for you: Hide Plugin Notifications or NoPluginBar.

  • Does not work since Firefox 40: Mozilla broke this solution including all addons that are based on that. Long term solution: Instead of finding new CSS hacks (that may again stop working in future releases), there should be an option in Firefox itself to disable this plugin notification bar. There exists already a bug report for that: bugzilla.mozilla.org/show_bug.cgi?id=942461 Since Firefox' bug tracking system is open for everyone, everyone can come and vote for that issue. That's in my opinion the best advice I can give to you. Any other solution would be only temporary.
    – manuel
    Aug 19, 2015 at 10:22

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