How to Disable the Pop-Up Blocker in Firefox

Not all pop-ups on websites are annoyances

A man uses a laptop computer.
A man uses a laptop computer. Nick David/Getty Images

Pop-up blockers prevent unwanted windows from opening without your permission on some websites. Mozilla's Firefox web browser includes a pop-up blocker, which is active by default.

What's Wrong With Pop-Ups?

Most pop-ups display ads, mailing list signups, and other promotional prompts that are often intrusive and annoying. The aggressive variety can be frustratingly difficult to close. Worse still, they can slow down your computer by consuming resources. Pop-ups usually appear on top of your browser window, but they can open up behind your browser window, too; these are sometimes called "pop-unders."

Situations in Which You Might Not Want to Block Pop-Ups

Most of the time, keeping your pop-up blocker active is useful. Sometimes, though, legitimate websites use pop-up windows to display forms or important information. For example, your bank's online bill-paying service might use a pop-up window to display your payees, such as credit card companies or public utilities, and the form you use to make payments to them. Blocking such pop-ups will prevent you from seeing important information, entering necessary details, and interacting with the site.

In addition, some websites include elements that pop-up blockers sometimes recognize as pop-ups but are actually integral to your experience of the page — for example, a video or animation. In this case, you might notice a blank area where such a display should appear.

How to Disable the Firefox Pop-Up Blocker

You can disable the pop-up blocker, either permanently for all websites or temporarily on a site you're currently visiting. More importantly, you can choose the sites on which you'd like to permit pop-ups by adding them to an exclusion list.

Follow these steps to change how Firefox's pop-up blocker functions.

  1. Click the Menu icon (three horizontal bars) > Preferences > Content.

  2. Uncheck the Block pop-up windows box.

  3. For an individual site, click on Exceptions and enter the URL of the website for which you want to allow pop-ups. Click Save Changes.

If You Change Your Mind

If you permit pop-ups for a site but decide to block them later:

  1. Go to Menu > Preferences  > Content > Exceptions.

  2. In the list of websites, select the URL you want to remove from the Exceptions list.

  3. Click on Remove Site.

  4. Click Save Changes.

Allowing Pop-Ups on an Android Phone

Firefox offers no straightforward option to allow or block pop-ups in the Android operating system, but there is a workaround:

  1. Type about:config in Firefox's address bar, at the top of the window.

  2. Search for dom.disable_open_during_load.

  3. Set it to false to allow pop-ups, and true to block them.

Allowing Pop-Ups on an iPhone or iPad

Similarly, you can allow pop-up windows on your Apple device:

  1. Tap the menu button (it looks like a hamburger).

  2. Swipe left. Select Settings.

  3. Toggle Block Pop-up Windows to Off (or On, to block them).

Firefox's pop-up blocker can't block all pop-ups. Sometimes, ads are designed not to look like pop-ups, so Firefox won't block those ads. Add-ons available for Firefox that can help with blocking unwanted content such as ads and provide additional control over what you see on the websites you visit. Search the Firefox Add-Ons website for such add-ons; among the most popular, for example, is Adblock Plus.