Add-ons, extensions, and themes

Understanding the risks of installing self-hosted extensions

Learn about the risks of installing extensions from third-parties and how to assess the trustworthiness of the source.

Add-on Badges

You’ll know if an extension is being regularly reviewed if it has one of the badges listed in this article.

Extensions in Private Browsing

You can set which Firefox extensions can run in private windows and which can't, when you install the extension or later on. Learn more.

Disable or remove Add-ons

Extensions and themes are types of add-ons for Firefox. This article describes how to disable and remove add-ons in Firefox.

Find and install add-ons to add features to Firefox

You can install different types of add-ons, such as extensions to add features to Firefox and themes to change its appearance. Learn more.

Add-on signing in Firefox

Learn about add-on signing and what to do if an extension you want to use could not be verified for use in Firefox.

Personalized extension recommendations

Learn more about how Firefox occasionally recommends extensions you may find interesting and how to opt-out.

Recommended Extensions program

Learn how extensions make the cut for the Recommended Extensions program and where they can be found.

Filelink for Large Attachments

Messages with large attachments are often rejected by mail servers. Thunderbird can use web-based storage services to send large file attachments.

Multi-Account Containers

Add Container tabs to Firefox with the Multi-Account Containers add-on, to separate your work and personal browsing.

Upgrade your graphics drivers to use hardware acceleration and WebGL

Firefox and plugins can use your graphics card to speed things up. To enable this or to fix problems, you may need to update the graphics card drivers.

Tips for assessing the safety of an extension

Here are a few tips for assessing the safety of a third party extension.

Manage your extensions using the extensions button in the toolbar

This article describes the new extensions button and how to manage your extensions and their permissions directly from the Firefox toolbar.

Use Firefox in another language

How to display Firefox in a different language.

JavaScript settings and preferences for interactive web pages

This article describes what JavaScript is and how to allow or block it on certain websites.

Thunderbird add-ons - frequently asked questions

Add-ons are extensions and other additions that add new functionality to Thunderbird or change its appearance.

Manage optional permissions for Firefox extensions

Learn how you can manage optional permissions for extensions in the Firefox Add-ons Manager.

Permission request messages for Thunderbird extensions

More information about each permission request you may encounter when installing an extension into Thunderbird.

Manage optional permissions for Firefox extensions on Android

Control data shared with Firefox for Android extensions by managing optional permissions.

Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

Learn how to find out if an extension, theme or hardware acceleration is causing a Firefox problem and what steps you can take to fix it.

An extension changed my New Tab page or home page

View and disable extensions or add-ons that change the new tab page or home page.

Get started with the Mozilla VPN extension

The VPN extension complements the main VPN app, offering flexible controls to secure your browsing activity and customize VPN settings without altering your device-wide VPN protection.

Permission request messages for Firefox extensions

Learn about permission requests when adding extensions to Firefox. Get details on each request for a clearer understanding.

Use themes to change the look of Firefox

A theme is a type of add-on that changes the visual appearance of Firefox. Learn how to find, install, and manage themes in Firefox.

Cannot remove an add-on (extension or theme)

This article describes how to uninstall an extension or theme that can't be removed normally. This includes problematic toolbars and search bars.

Manage extension shortcuts in Firefox

Manage your add-on shortcuts through the Manage Preferences menu in about:addons.

Send plugin crash reports to help Mozilla improve Firefox

When a plugin crashes, you may see a message with a link to send a crash report. Sending these reports before reloading the page helps us improve Firefox.

Install themes to change the look of Thunderbird

A theme is a type of add-on which changes the visual appearance of Thunderbird. Learn how to find, install, and manage themes within Thunderbird.

Why does Mozilla disable some add-ons from running in Firefox?

Add-ons that violate Mozilla's add-on policies or jeopardize user safety and privacy may be restricted or blocked from running in Firefox.

Why is there an OpenH264 plugin in Firefox?

Firefox comes with the OpenH264 add-on to support WebRTC or video communication.

Facebook Container - Prevent Facebook from tracking you on other websites

Facebook Container is an add-on that you can install on Firefox to prevent Facebook from tracking your activity on other websites.

Use the Save to Pocket extension for Google Chrome

Learn how to use the Save to Pocket extension in Google Chrome

A program on your computer interferes with the Mozilla VPN extension

You got a message saying that “A program on your computer may be causing issues with the Mozilla VPN extension”. Here's how you can fix that.

Installing an Add-on in Thunderbird

Add-ons add functionality to Thunderbird or change its appearance. Learn how to install add-ons to Thunderbird.

Firefox Translations Add-on

Translate web pages in Firefox when you visit a site that's in another language, without using the cloud.

Install the Pocket extension in your browser

You can install the Save to Pocket extension for Google Chrome, Safari, Microsoft Edge and most Chromium-based browsers like Brave, Vivaldi, and Opera.

Disable VPN protection for a specific website

The Mozilla VPN extension allows you to choose the websites you wish to protect and the ones you don't. This article describes how it works.

Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?

NPAPI plugins, including Adobe Flash Player, no longer load in Firefox. Learn more about this change.

Built-in themes in Firefox - alternative to complete themes

How to enable Firefox's built-in themes.

How to add devices to your Mozilla VPN subscription

A subscription to Mozilla VPN lets you install the application on up to five devices. Learn how to add and remove devices after installing the app.

Re-enable add-ons that were disabled when updating Firefox

Many add-ons are automatically compatible with the latest Firefox. For those that aren't, we'll show you how to search for new versions or find an alternative.

Remove a toolbar that has taken over your Firefox search or home page

This article will help you remove unwanted third-party toolbars from Firefox and restore the default search, New Tab and home page settings.

How to Customize Toolbars

This article explains how to customize the position and contents of Thunderbird toolbars.

Access your add-ons with a Mozilla account

The addons.mozilla.org (AMO) site is using Mozilla accounts to offer a more integrated experience across all Mozilla services and products.

Facebook Container isn't working

What to do if Facebook Container doesn't work.

Recommended Firefox extensions for families and students

This article lists some extensions for parents and students that you can add to Firefox, to enhance browsing and help you stay productive.

Use the Save to Pocket extension for Safari

Information about using Pocket's save extension for Safari

Orbit Frequently Asked Questions

This article addresses frequently asked questions about Orbit.

How to Install and Use another Language in the Dictionary on Thunderbird

How to install and use additional language dictionaries on Thunderbird.

Get help with Firefox Developer Edition

Firefox now has a version built especially for developers. Learn where to get help.

How to add the translate add-on to Firefox

Seamlessly translate webpages in Firefox.

Report extensions and themes for abuse

Discover what constitutes inappropriate content or behavior in an extension or theme, and see how to report any abuse you find.

Review installed extensions

Reviewing the extensions you have installed periodically can make it harder for malicious extensions to put your security and privacy at risk.

Unable to uninstall add-ons (extensions or themes)

This article describes how to uninstall an extension or theme that can't be removed normally.

X-Mouse Button Control in Firefox 110

Learn about an issue with X-Mouse Button Control in Firefox 110 for Windows.

Using the Save to Pocket extension in Microsoft Edge

Information about using the Save to Pocket extension for Microsoft Edge.

Integrate Firefox Relay into the Firefox Password Manager

Learn how to integrate Firefox Relay into the Firefox Password Manager to create and manage email masks directly.

Change your location for a specific website

The Mozilla VPN extension allows you to set a particular location through which you want to access a given website. Learn about this feature here.

Manage the VPN extension preferences

After configuring VPN preferences for different websites, you may want to review them to confirm they meet your expectations. Follow these steps to do so.

Unable to install add-ons (extensions or themes)

This article describes various reasons why you are not able to install a Firefox add-on and possible ways to fix the problem.

Flash-based videos and sound do not play correctly

Just a redirect.

Certificates

Add-Ons FAQ

How can I digitally sign and encrypt emails?

Installing and Using another Language in the Dictionary

Uninstall Firefox for Android extensions

How to uninstall Firefox for Android add-ons/extensions

What is search hijacking?

This article describes the types of search hijacking that occur.

How to update add-ons

This article explains how to update your Firefox add-ons from the Extensions panel in the Add-ons Manager.

How is Facebook Container different from Multi-account Containers?

The difference between Facebook Container and Multi-Account Containers

Unable to install add-ons (extensions or themes) in Thunderbird

This article describes various reasons that would cause an add-on not to be able to be installed and what you can do to fix the issue.

Install system add-ons on Firefox for Enterprise

How to configure your add-on to run on Firefox for Enterprise without having to sign it.

Block add-ons in Firefox for Enterprise

Control whether users can install or use add-ons in your organization.

Lightbeam extension for Firefox is no longer supported

Mozilla ended official support of the Lightbeam extension in October 2019 and has no plans to resume maintenance of it in the future.

Troubleshoot issues related to add-ons

Add-ons can cause issues in Firefox. This article provides more information on how you can troubleshoot Firefox issues related to add-ons.

Change your theme in Firefox Focus for Android

Firefox Focus for Android has built-in light and dark themes so you can customize its appearance. You can also choose to have the theme follow your device theme.

Change your theme in Firefox Focus for iOS

Firefox Focus for iOS has built-in light and dark themes so you can customize its appearance. You can also choose to have the theme set by your system.

Install the Firefox Relay extension on Firefox for desktop

Extensions customize and add functionalities to Firefox. Add the Firefox Relay extension to generate a mask when you register on websites.

Site Permission Add-ons

Sites can ask to install permission add-ons that modify Firefox’s default security behavior to give them extra privileges. Learn more.

Install the Firefox Relay extension in Firefox for Android

Start generating email masks from your mobile device. This article provides step-by-step instructions for downloading and setting up the Relay extension in Firefox for Android.

Why aren’t my add-ons working on some websites?

Learn why some Firefox extensions have been disabled on certain websites, how to manage these limits, and explore alternative solutions.

Troubleshooting Save Button issues with Pocket Chrome extension

Resolving common issues saving via the Pocket extension for Google Chrome

Using the Pocket Must Reads extension in Google Chrome

How to use the Must Reads extension in the new tab page of Google Chrome. Note: this extension is no longer supported.

Using the Save to Pocket extension in Brave, Opera and Vivaldi

Information about the Save to Pocket extension for Chromium browsers including Brave, Opera and Vivaldi.

How will DNS work when using the VPN extension?

Learn how your DNS (Domain Name System) settings work while using your Mozilla VPN extension.

What to do if another extension interferes with the Mozilla VPN extension

If you're using the Mozilla VPN extension and encounter a message about other extensions interfering, follow this steps to fix it.