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

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 pop-unders 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 (if it hasn’t been previously dismissed – see below), as well as an icon in the location bar.

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

Allow/Block pop-ups for this site
Edit Pop-up Blocker OptionsPreferences…
Don't show this message when pop-ups are blocked
(show the blocked pop-up)

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

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

Pop-up blocker settings

To access the pop-up blocker settings:

At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.
Click the menu button and choose Options.Preferences.
Select the Content panel.
In the Content panel below Pop-ups:

Uncheck the box next to Block pop-up windows to disable the pop-up blocker altogether.
A click on Exceptions… opens a dialog box with a list of sites that you want to allow to display pop-ups.
The dialog box offers you the following choices:

Allow: Click this to add a website to the exceptions list.
Remove Site: Click this to remove a website from the exceptions list.
Remove All Sites: Click this to remove all of the websites in the exceptions list.

Note: Blocking pop-ups may not always work and may interfere with some websites. For more information, see the What are Pop-ups? section above.

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 appearance of the window.

If you see the location bar with the Site Identity button (a globe, padlock or warning triangle) button in the pop-up window, the pop-up is coming from Firefox.

If you don't see the Site Identity button button, you may have malware on your computer that causes the pop-ups. For help, see Troubleshoot Firefox issues caused by malware.

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

At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.
Click the menu button and choose Options.Preferences.
Select the Content panel.
Make sure the Block pop-up windows checkbox is checked.
To the right of Block pop-up windows, click the Exceptions... button. A dialog box will open and lists all the sites that are allowed to show pop-ups.
If the site that's opening pop-ups is listed here, select it and press Remove Site.
Click CloseClose the Allowed Sites - Pop-ups window.
Click OK to close the Options window.Click Close to close the Preferences window.Close the Preferences window. Close the about:preferences page. Any changes you've made will automatically be saved.

At the top of the Firefox window, click on the Firefox button and then select Options.At the top of the Firefox window, click on the Tools menu and then select Options.On the menu bar, click on the Firefox menu and select Preferences....At the top of the Firefox window, click on the Edit menu and select Preferences.
Click the menu button and choose Options.Preferences.
Select the Content panel.
Make sure the Block pop-up windows checkbox is checked.
To the right of Block pop-up windows, click the Exceptions... button. A dialog box will open and lists all the sites that are allowed to show pop-ups.
If the site that's opening pop-ups is listed here, select it and press Remove Site.
Click on Save changes to update your changes.
Click OK to close the Options window.Click Close to close the Preferences window.Close the Preferences window. Close the about:preferences page. Any changes you've made will automatically be saved.

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 intentional, so that Firefox doesn't block pop-ups that websites 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.

Mozilla surveys

When you visit a Mozilla website, sometimes you'll see a pop-up asking you to participate in a survey. The only third-party that Mozilla ever uses for surveys is SurveyGizmo, which has been vetted by our legal and privacy teams. The Firefox pop-up blocker doesn't block these pop-ups.

Firefox