Changing the Language of Firefox from English to other language

Yesterday i was stuck with a customer data where the language of the customer was french. The customer used jmeter for load testing our product and he used some french html source in it .In order to crack his data , i had 2 options one was to change the OS to french and the second was to change the Firefox language to french and see the source .

Steps to change the Firefox language to french

Open Firefox -> Tools tab present in the top -> Click on Options ->Content Tab -> Choose Button present next to the languages in the window ->In this window , click on the "Select a language to add" dropdown and go to the language you'd like to add -> Choose the language , add them and click on ok






The localized versions of firefox for different locations is this http://www.mozilla.com/en-US/firefox/all.html .
One can get a localized version from the above link

Thirdly there is Firefox add-on which can change the Firefox language . The add is called the quick locale switcher which can downloaded from this link https://addons.mozilla.org/en-US/firefox/addon/quick-locale-switcher/