How to Block Pop–ups in Firefox

Written by Jack Lloyd

Last Updated: June 3, 2021 Tested

This wikiHow teaches you how to prevent pop-up ads from appearing in your Firefox browser on both desktop and mobile platforms. While it is impossible to eliminate 100 percent of pop-ups in Firefox or any other browser, you can decrease the number of pop-ups to virtually none by using Firefox's built-in pop-up blocker. You can also use a Firefox extension called Adblock Plus to block more obtrusive ads on desktop, while mobile users can download the free Firefox Focus app to browse ad-free.

Method 1

Method 1 of 5:

Using Firefox Settings on Desktop

1
Open Firefox. Its app icon resembles an orange fox wrapped around a blue globe.
2
Click ☰. It's in the top-right corner of the page. A pop-out window will appear.

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3
Click Options. You'll find this in the pop-out window.
- On a Mac, you'll click Preferences instead.
4
Click Privacy & Security. It's a tab on the far-left side of the page.
5
Scroll down to the "Permissions" section. This section is near the bottom of the page.
6
Check the "Block pop-up windows" box. It's near the bottom of the "Permissions" section. Doing so ensures that Firefox will prevent pop-up windows, including ads, from appearing.
- If this box is checked, Firefox is already blocking pop-up windows.

Method 2

Method 2 of 5:

Using Firefox Settings on iPhone

1
Open Firefox. Tap the Firefox app icon, which resembles an orange fox wrapped around a blue globe.
2
Tap ☰. This is in the bottom-right corner of the screen. Tapping it prompts a pop-up window.
3
Tap Settings. It's at the bottom of the pop-up window. Doing so opens the Settings window.
4
Tap the white "Block Pop-up Windows" switch
. The switch will turn blue, signifying that pop-ups are now blocked in Firefox on your iPhone.
- If the switch is blue, pop-ups are already being blocked.

Method 3

Method 3 of 5:

Using Firefox Settings on Android

1
Open Firefox. Tap the Firefox app icon, which resembles an orange fox wrapped around a blue globe.
2
Tap the address bar. It's at the top of the screen.
- You may first have to scroll up to cause the address bar to appear.
3
Go to the system settings page. Type about:config into the address bar and tap the "Search" key.
4
Tap the search bar. It's in the top-right corner of the screen.
5
Search for the pop-up blocker option. Type in dom.disable_open_during_load and press the "Search" key.
6
Make sure this option says "false" below it. If you see "true" written below the dom.disable_open_during_load text, Firefox is already blocking pop-ups.
7
Turn on the pop-up blocker. Tap dom.disable_open_during_load, then tap Toggle.
8
Restart Firefox. Close the Firefox app, then re-open it. Firefox will now block ads, including pop-ups.

Method 4

Method 4 of 5:

Using Adblock Plus

1
Open Firefox on a computer. Its app icon resembles an orange fox wrapped around a blue globe.
- Unfortunately, you cannot install Adblock Plus for use with Firefox on an iPhone or Android.
2
Open the Adblock Plus extension page. This is the page from which you can download Adblock Plus.
3
Click ＋ Add to Firefox. It's a blue button in the middle of the page.
4
Click Add when prompted. You'll see this appear at the top of the window. Doing so installs Adblock Plus on Firefox.
5
Click the Adblock Plus icon. It's a stop sign-shaped icon with a white "ABP" written across it in the upper-right side of the Firefox window. Clicking it prompts a drop-down menu.
6
Click Options. This option is at the bottom of the drop-down menu. The Adblock Plus Options page will open.
7
Uncheck the "Allow Acceptable Ads" box. It's in the "ACCEPTABLE ADS" section of the page.
8
Browse pop-up free. Now that Adblock Plus is installed, you should be able to avoid the bulk of ads—pop-up or otherwise—in your Firefox desktop browser.
- You may occasionally still see ads, and some websites will require you to disable your adblocker in order to view their content.
- To disable Adblock Plus, click its icon (you may first have to click ☰ in the top-right corner of the window to see the icon), then click Enabled on this site.

Method 5

Method 5 of 5:

Using Firefox Focus

1
Understand how to use Firefox Focus. Firefox Focus is a free version of Firefox for iPhone and Android smartphones; it has a built-in ad blocker which will prevent most pop-ups and other egregious forms of advertising from appearing.
- Firefox Focus is not available on Windows or Mac computers.
2
Install the Firefox Focus app. To install it, open the
App Store (iPhone) or
Play Store (Android), then do the following:
- iPhone — Tap Search, tap the search bar, type in firefox focus, tap Search, tap GET to the right of the Firefox Focus icon, and enter your Touch ID or Apple ID when prompted.
- Android — Tap the search bar, type in firefox focus, tap the "Search" icon, and tap INSTALL under the Firefox Focus heading.
3
Open Firefox Focus. Once it finishes downloading, tap OPEN in your app store, or tap the purple-and-white Firefox Focus app icon.
4
Tap Skip. It's in the upper-left corner of the screen.
5
Browse normally. Since Firefox Focus both includes and activates by default an aggressive ad blocker, you'll be able to browse without having to worry about pop-ups.