Duolingo (/ˌdˈlɪŋɡ/ doo-oh-ling-goh or /ˌdjuːˈlɪŋɡ/ dyoo-oh-ling-goh) is a free language-learning platform that includes a language-learning website and app, as well as a digital language proficiency assessment exam. Duolingo offers all its language courses free of charge. As of April 2016, the language-learning website and app offer 59 different language courses across 23 languages; with 23 additional courses in development. The app is available on iOS, Android and Windows 8 and 10 platforms with about 120 million registered users across the world.


Business model

Core services of the platform are available for free. Duolingo uses only very limited advertising in its android/iOS app. There are no subscription fees for the tutorials. However, there were instances when the platform has been used for paid translation purposes.[23] In July 2014, Duolingo started a language certification service, Test Center, as a new business model. In June 2015, a Duolingo spokesperson confirmed that the company has been backing away from the translation business and in the future will instead focus on language certification and other (not yet announced) business opportunities.