Install and manage add-ons

Add-on Badges

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

Permission request messages for Firefox extensions

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

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.

Refresh Firefox - reset add-ons and settings

A Refresh can fix many issues by restoring Firefox to its default state while saving essential information like bookmarks and passwords.

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.

Recommended Extensions program

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

Personalized extension recommendations

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

Multi-Account Containers

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

Tips for assessing the safety of an extension

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

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.

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.

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.

Mozilla VPN - FAQ

Find answers to some of the most common questions about Mozilla VPN in this article.

Manage optional permissions for Firefox extensions

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

Use Firefox in another language

How to display Firefox in a different language.

Manage extension shortcuts in Firefox

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

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.

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.

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.

Permission request messages for Thunderbird extensions

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

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.

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 on Android

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

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.

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.

How to Customize Toolbars

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

Built-in themes in Firefox - alternative to complete themes

How to enable Firefox's built-in themes.

Unable to install add-ons (extensions or themes)

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.

Open Search

Instantly take part of a message and search for it in Bing, Yahoo, Twitter or other websites.

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

Since the release of Firefox version 52 in March 2017, NPAPI plugins no longer load, except for Adobe Flash. Learn more about this change.

Reporting 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.

Add Search Engine to Open Search

Open Search enables Thunderbird users to search various websites from within Thunderbird. This article describes how to add additional websites to the Open Search interface.

How to Customize the New Mail Sound

Learn how to customize the sound that plays when a new email message is received.

Installing an Add-on in Thunderbird

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

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.

How to update add-ons

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

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.

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.

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.

Unified Toolbar

Intro to the Unified Toolbar and how to customize the buttons for the different toolbars for: Mail, Address Book, Calendar, Tasks, Chat and Settings "Spaces."

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.

Flash-based videos and sound do not play correctly

Just a redirect.

Certificates

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

How to install and use additional language dictionaries on Thunderbird.

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

Why is there an OpenH264 plugin in Firefox?

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

How to add the translate add-on to Firefox

Seamlessly translate webpages in Firefox.

How is Facebook Container different from Multi-account Containers?

The difference between Facebook Container and Multi-Account Containers

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.

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.

Unable to uninstall add-ons (extensions or themes)

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

Firefox Translations Add-on

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

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.