Add-ons are small pieces of software created by people all over the world, that add new features or functionality to your installation of Firefox. Add-ons can augment Firefox with new search engines, foreign-language dictionaries, or change the visual appearance of Firefox. Through add-ons, you can customize Firefox to meet your needs and tastes.

• Extensions
  Extensions add new features to Firefox, or modify existing ones. There are extensions that allow you to block advertisements, download videos from websites, integrate more closely with websites like Facebook or Twitter, and add features you see in other browsers.
• Themes
  Themes change the visual appearance of Firefox. Some themes simply change the toolbar's background colors; other themes make Firefox look like a completely different program.
• Plugins
  A plugin is a piece of software that manage internet content that Firefox is not designed to process. These usually include patented formats for video, audio, online games, presentations, and more. Plugins are created and distributed by other companies.

Troubleshooting add-ons

For information on troubleshooting problems with extensions, plugins, or themes, see the articles below:

• Unable to install add-ons
• Uninstalling add-ons
• Cannot uninstall an add-on
• Troubleshooting extensions and themes
• Troubleshooting plugins