Language packs are add-ons that let you to have more languages available for the user interface of Firefox. This article describes how:
If you are searching how to control the preferred languages for websites that offer its contents in multiple languages, see Settings for web content, pop-ups, fonts, and languages.
To see what language packs you have installed:
At the top of the Firefox window, click on the buttonOn the menu bar, click on the menuAt the top of the Firefox window, click on the , and then click menu . The Add-ons Manager tab will open. Click the menu button and choose . The Add-ons Manager tab will open.
If you don't have apanel, don't worry. It's hidden if you don't have language packs installed. The same goes for a few other uncommon types of add-ons.
If you want to remove a language pack, see Disable or remove Add-ons.
Unlike themes, enabling a language pack in the Add-ons Manager only does the languages it provides available. To change the preferred language for the interface:
In the address bar, type about:config and press EnterReturn.
At the top of the Firefox window, click on the button and then select At the top of the Firefox window, click on the menu and then select On the menu bar, click on the menu and select At the top of the Firefox window, click on the . menu and select
Click the menu button and then click ExitQuit .
When you start Firefox again, you will see the interface in the new specified language.