Duolingo

Duolingo is the world's leading language-learning platform, making education free and accessible to millions through its innovative, gamified approach. Founded in 2011 by Carnegie Mellon University professor Luis von Ahn and his Swiss-born graduate student Severin Hacker, Duolingo has revolutionized how people learn languages by combining rigorous pedagogy with game-like engagement mechanisms. With over 130 million monthly active users and 50 million daily active users as of early 2025, Duolingo has become the most popular language-learning application globally.

The company went public in July 2021 at a $3.7 billion valuation and has since grown to a market cap of $17.7 billion by mid-2025—a 247% surge. Duolingo offers courses in 42 languages ranging from widely-spoken ones like English, Spanish, and French to less common languages like Welsh, Irish, Navajo, and even constructed languages like Klingon. The platform has expanded beyond languages to include mathematics, music, and chess, demonstrating its vision to become a comprehensive multi-subject learning platform.

Duolingo's freemium model allows anyone to access courses for free, supported by advertising, while Super Duolingo and Duolingo Max premium subscriptions (10.3 million paid subscribers) offer ad-free experiences and AI-powered features. The company generated $748 million in revenue in 2024, with projections of $991 million for 2025, representing 40% year-over-year growth. Duolingo's success stems from its unique blend of behavioral psychology, adaptive learning algorithms, AI integration including GPT-4-powered features, and the iconic green owl mascot Duo that has become a cultural phenomenon. Headquartered in Pittsburgh, Pennsylvania, Duolingo employs over 800 people and maintains a >90% annual employee retention rate, demonstrating exceptional company culture alongside its educational mission.