Pop-up blocker

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This document explains all of the optionspreferences available in Mozilla Firefox for controlling pop-ups.

Table Of Contents

What are Pop-ups?

Pop-up windows, or pop-ups, are windows that appear automatically without your permission. They vary in size but usually don't cover the whole screen. Some pop-ups open on top of the current Firefox window, while others appear underneath Firefox (pop-unders).

Firefox allows you to control both pop-ups and popunders through the Content panel in the OptionsPreferences window. Pop-up blocking is turned on by default, so you don't have to worry about enabling it to prevent pop-ups from appearing in Firefox.

When blocking a pop-up, Firefox displays an information bar, as well as an icon in the status bar.







When you click either the OptionsPreferences button in the information bar or the icon in the status bar, a menu is displayed with the following choices:

Blocking pop-ups may interfere with some web sites: Some web sites, including some banking sites, use pop-ups for important features. Blocking all pop-ups disables such features. To allow specific web sites to use pop-ups, while blocking all others, you can add specific web sites to the list of allowed sites.

Blocking pop-ups doesn't always work: Although Firefox blocks most pop-ups, some web sites may show pop-ups using uncovered methods, even when blocked.

Pop-up Blocker OptionsPreferences

To access the Pop-up Blocker OptionsPreferences:

  1. At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
  2. Select the Content panel.

From there, you can do the following things:

  • Block pop-up windows: Deselect this optionpreference to disable the pop-up blocker altogether.
  • Exceptions: This is a list of sites that you want to allow to display pop-ups.







    The dialog has the following choices:
    • Allow: Click this to add a web site to the exceptions list.
    • Remove Site: Click this to remove a web site from the exceptions list.
    • Remove All Sites: Click this to remove all of the web sites in the exceptions list.

Note: Blocking pop-ups may not always work and may interfere with some web sites. For more information about blocking pop-ups, see What are Pop-ups.

Pop-ups not being blocked

Is the pop-up coming from Firefox?

The pop-up may not actually be coming from Firefox. You can determine where the pop-up is coming from by the icons it has and the title at the top.

  • A Firefox icon and "Mozilla Firefox" in the title: keep reading below.
  • Everything else: you may have malware on your computer that causes the pop-ups. Scan your computer for viruses and spyware.

This pop-up comes from Firefox. It has a Firefox icon and the text Mozilla Firefox.

Is the pop-up blocker on and enabled for this site?

  1. At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
  2. Select the Content panel.
  3. Make sure the Block pop-up windows checkbox is checked.
  4. To the right of Block pop-up windows, click the Exceptions... button. A dialog will appear that shows all the sites that are allowed to show pop-ups.
  5. If the site that's opening pop-ups is in the list, select it and press Remove Site.
  6. Click CloseClose the Allowed Sites - Pop-ups window.
  7. Click OKClose the preferences window.

Is the pop-up shown after a mouse click or a key press?

Certain events, such as clicking or pressing a key, can spawn pop-ups regardless of if the pop-up blocker is on. This is so that Firefox doesn't block pop-ups that web sites need to work.

Is it a true pop-up window?

Sometimes ads are designed to look like windows, but really aren't. Firefox's pop-up blocker can't stop these ads.

This page has fake pop-up windows. Some signs include the color of the title bars being wrong and an incorrect or missing icon in the top left.


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Page last modified on Thursday 21 of August, 2008 13:29:34 PST.
Contributors to this page: Chris_Ilias and mozilla_help_viewer_project .
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