LangId is a free web service that allows you to identify in which language was written any text you need to analyze.
LangID is the quickest way to retrieve informations about a language you don’t know.
Most of the free translations services available online ask you to select the language you want to translate a text from. This means that if you don’t know what language it is you can not translate it in your language
Using LangID you can understand in which language a text was written and then use an external service to translate it.