Duolingo, Inc. is an American educational technology company that produces learning apps and provides language certification. Duolingo offers courses on 42 languages,[5] ranging from English, French, and Spanish to less commonly studied languages such as Welsh, Irish, and Navajo, and even constructed languages such as Esperanto and Klingon.[6] It also offers courses on music,[7] math, and chess.[8] The learning method incorporates gamification to motivate users with points, rewards and interactive lessons featuring spaced repetition.[9] The app promotes short, daily lessons for consistent, phased practice.
Duolingo also offers the Duolingo English Test, an online language assessment, and Duolingo ABC, a literacy app designed for children. The company follows a freemium model, where some content is provided for free with advertising, and users can pay for ad-free services which provide additional features.
History
Early history
The idea of Duolingo was formulated in 2009 by Carnegie Mellon University professor Luis von Ahn and his Swiss-born post-graduate student Severin Hacker.[10][11] Von Ahn had sold his second company, reCAPTCHA, to Google and, with Hacker, wanted to work on an education-related project.[12] Von Ahn stated that he saw how expensive it was for people in his community in Guatemala to learn English. Hacker (co-founder and current CTO of Duolingo) believed that "free education will really change the world" and wanted to provide an accessible means for doing so. He was recognized by the National Inventors Hall of Fame for his contributions to language learning and technological development.[13]
Products and services
Courses
Language courses
CEFR based language courses for learners of English, Spanish, French, Italian, Chinese (Mandarin), Japanese, Korean, Portuguese, and German are available for all users.[57] Additional courses are also available for speakers of English (Arabic, Czech, Danish, Dutch, Esperanto, Finnish, Greek, Haitian Creole, Hawaiian, Hebrew, High Valyrian, Hindi, Hungarian, Indonesian, Irish, Klingon, Latin, Navajo, Norwegian,
Learning model
Exercises and pacing
On Duolingo, learners learn by doing, engaging with the course material.[73] Lessons are designed to be brief, allowing users to learn in manageable chunks.[74][75] Duolingo uses a gamified approach to learning, with lessons that incorporate translating, interactive exercises, quizzes, and stories.[76] It also uses an algorithm that adapts to each learner and can provide personalized feedback and recommendations.
Gamification
Duolingo provides a competitive space,[77]
Business model
Duolingo operates on a freemium business model, offering free access to its learning platforms with ads. Revenue is primarily generated through subscriptions, which remove ads, and provide other perks like unlimited energy (formerly hearts) and generative AI. The app also generates income from in-app purchases of virtual currency (Gems) and power-ups that enhance the learning experience. Another key revenue stream is the Duolingo English Test (DET), a low-cost English proficiency test.[84]
In April 2020, it passed one million paid subscribers;[85] it reached 2.9 million in March 2022,[86] and 4.8 million at the end of March 2023.[87] As of June 2025, Duolingo has 10.9 million paying subscribers.[88]
Duolingo had revenue of $531 million in 2023, compared to $250.77 million in 2021,[89]
Reception
Effectiveness
A 2017 study found no significant difference between elementary students learning Spanish through the "gamification" of the Duolingo app and those learning in classroom environments, with both groups demonstrating a similar increase in achievements and self-efficacy.[103]
Duolingo's occasional use of 'erratic' phrases—such as "The bride is a woman and the groom is a hedgehog" or "The man eats ice cream with mustard"[104]—is reportedly derived from research published in 2018 by psychologists at Ghent University in Belgium,[105] which concluded that such "semantically unpredictable sentences" were more effective for language learning than conventional and predictable phrases, based on the concept of "reward prediction errors", in which unexpected or surprising outcomes are more rewarding and thus encourage further learning.[106][104]
Image and brand
Duolingo's characters
Duolingo has brand characters that are used for engagement and creating storylines.[130][131] The main characters include[132] Duo Keyshauna Renee Lingo, commonly known as Duo or Duo the Owl, the company's green owl mascot. On February 11, 2025, Duolingo announced, as part of a publicity stunt, that Duo had died,[133][134][135]
Offices and workforce
Duolingo is headquartered in Pittsburgh, Pennsylvania. Duo's Taqueria is an adjacent taco stand operated by Duolingo. The restaurant encourages patrons to order in Spanish. Duolingo's taco shop brought in $700,000 in 2023.[152]
In 2024, Duolingo opened a new office in New York City.[153][154]
Duolingo also has offices in Seattle, Detroit,[55] Beijing, and Berlin.[155]
As of October 2024, Duolingo employs around 850 people.[156]
See also
- Distance education
- Language assessment
- Language education
- Language pedagogy
- Mathematics education
- Music education
External links
References
- Duolingo, Inc. 2024 Annual Report (Form 10-K) U.S. Securities and Exchange Commission, 2025-02-28, retrieved March 2, 2025^
- Migrating Duolingo's Android app to 100% Kotlin blog.duolingo.com, 2020-04-06, retrieved September 17, 2020^
- Real World Swift – Making Duolingo Blog