Duolingo is an American educational technology company which produces learning apps and provides language certification.

Online education, Professional certification, Products: Duolingo, Duolingo Math, Duolingo ABC, Duolingo English Test

Services: Language and mathematics courses and tests.

The platform was founded in 2011 by Luis von Ahn and Severin Hacker and has since grown to become one of the most popular language learning apps in the world.

Duolingo offers a wide range of language courses, teaching over 100 languages, from popular languages such as English, Spanish, French, and German, to less commonly studied languages such as Welsh, Irish, and Swahili. Duolingo also offers the Duolingo English Test certification program and a literacy app for children called Duolingo ABC, and the company released an elementary level math app called Duolingo Math currently exclusive to iOS.

The company uses a fermium model with over 500 million registered users. Duolingo offers a premium service which eliminates advertising and offers more features.