Duolingo

Duolingo is a language-learning company founded in 2011 in Pittsburgh by Luis von Ahn and Severin Hacker. Its free, gamified app teaches more than 40 languages to over 100 million monthly active users and over 30 million daily users.

Duolingo has expanded beyond languages into math, music, and chess products, and monetizes through Super Duolingo subscriptions, Duolingo Max (AI-powered plan), and the Duolingo English Test.

The company went public on NASDAQ in 2021 (DUOL) and reported more than $700 million in annual revenue. Luis von Ahn, co-inventor of CAPTCHA and reCAPTCHA, remains CEO.