Duolingo is a language-learning platform that includes a language-learning website and app, as well as a digital language proficiency assessment exam. The company was founded in 2011 by Luis von Ahn and Severin Hacker. Duolingo offers courses in over 40 languages, including Spanish, French, German, Italian, and Chinese. The platform is free to use, but users can pay for additional features. Duolingo has won numerous awards for its innovative approach to language learning.