Duolingo, Inc. (DUOL)

Duolingo, Inc. is a technology company founded by Luis von Ahn and Severin Hacker with a mission to develop the best education in the world and make it universally available, targeting equitable access to high-quality learning through mobile-first, gamified products. As of December 31, 2025, the company employed more than 900 people, including over 430 engineers, and its flagship Duolingo App has organically become the world's most popular way to learn languages and the top-grossing Education app in app stores, offering more than 250 language courses to over 130 million monthly active users, of whom approximately 9% are paid subscribers. The company operates a freemium business model where core content is free (supported by ads) while Super Duolingo and the premium Duolingo Max subscription tiers, including a family plan, provide additional features, some AI-powered.

Beyond languages, Duolingo has expanded into Math, Music, and a newly launched Chess course, all integrated into its core app, reflecting its strategy to broaden into additional subjects using the same gamified, data-driven approach. The company also operates the Duolingo English Test, an online, on-demand, AI-driven English proficiency assessment accepted by over 6,100 education programs worldwide, including elite universities, as well as Duolingo for Schools and the children's literacy app Duolingo ABC. Duolingo's growth is driven by two reinforcing "flywheels"—a learning flywheel, where scale and data improve engagement and efficacy, and an investment flywheel, where user growth and subscription revenue fund further product innovation—supported by heavy use of A/B testing, machine learning, and what the company believes is the world's largest language-learning dataset, generated from nearly 2 billion daily exercises.

Growth has historically been driven primarily by organic word-of-mouth and brand virality, supplemented by targeted paid acquisition, brand marketing, owned media (email/push notifications), and localized geographic expansion efforts. The company faces competition from other online and offline language-learning platforms, literacy and assessment providers, and math, music, and chess learning products, and competes based on brand strength, user engagement, technology, and continuous product innovation. Duolingo holds trademarks (including "Duolingo" and its Duo mascot), copyrights, domain names, and has filed patent applications related to language proficiency testing technology, while relying on confidentiality agreements to protect trade secrets.

The company is subject to extensive and evolving regulation across privacy, data protection, consumer protection, payment processing, and child protection laws in the U.S. and internationally, including GDPR (EU/UK), Brazil's LGPD, and China's Cybersecurity Law, Data Security Law, and Personal Information Protection Law, with compliance measures such as age-gating for users under 13 under COPPA. Key risks disclosed include user growth and engagement, competitive pressures, profitability sustainability, tax valuation allowance impacts, reliance on third-party platforms and cloud infrastructure, success of AI/ML development, and macroeconomic conditions affecting the business.