Add-ons, extensions, and themes

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.

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.

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.

Personalized extension recommendations

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

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.

Multi-Account Containers

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

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.

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.

Manage optional permissions for Firefox extensions on Android

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

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.

Manage optional permissions for Firefox extensions

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

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.

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.

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.

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.

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.

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.

Permission request messages for Thunderbird extensions

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

I found a fake Firefox update

What to do if you spot fake notices claiming to contain an "urgent" or "critical" Firefox update.

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.

Thunderbird add-ons - frequently asked questions

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

Manage extension shortcuts in Firefox

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

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.

Open Search

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

Use Firefox in another language

How to display Firefox in a different language.

Why is there an OpenH264 plugin in Firefox?

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

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 is Facebook Container different from Multi-account Containers?

The difference between Facebook Container and Multi-Account Containers

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.

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.

Install the Pocket extension in your browser

How to install the Pocket save extension for your web browser

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.

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.

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.

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.

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.

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

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 can I digitally sign and encrypt emails?

How to Customize the New Mail Sound

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

Installing and Using another Language in the Dictionary

Installing an Add-on in Thunderbird

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

How to update add-ons

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

Built-in themes in Firefox - alternative to complete themes

How to enable Firefox's built-in themes.

How to add the translate add-on to Firefox

Seamlessly translate webpages in Firefox.

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.

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.

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.

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."

userChrome.css and .js and userContent are unsupported

userChrome.css, userChrome.js, userContent.css and userContent.js are unsupported because they can break at any time and are difficult to troubleshoot.

Using the Save to Pocket extension for Google Chrome

Learn how to use Pocket's save extension in Google Chrome

Use the Save to Pocket extension for Safari

Information about using Pocket's save extension for Safari

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 Microsoft Edge

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

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.

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.