Build story · United States · 2011–2023
Duolingo: making language learning a daily habit
Duolingo offered free language lessons and used streaks, game mechanics, and relentless A/B testing to turn learning into a habit for tens of millions of daily users.
By Shivam Bhandari · Reviewed 31 October 2026 · How we write
by the numbers
- Launch
- 2012
- IPO
- 2021
- Revenue (2023)
- about $531 million
- Monthly users (end 2023)
- about 88 million
- Daily users (end 2023)
- about 27 million
What happened
Carnegie Mellon professor Luis von Ahn, who had sold reCAPTCHA to Google, and his student Severin Hacker launched Duolingo in 2012 with a mission of free education. Lessons were short, mobile, and felt like a game.
The company tested almost everything. Daily streaks, reminders from its green owl mascot, leaderboards, and leagues were refined through constant experiments. The streak became so powerful that many users kept long streaks running for years. Revenue came from ads and a subscription that removed ads and added features.
Duolingo went public in 2021. In 2023 it earned about $531 million in revenue, with more than 88 million monthly users and about 27 million daily users by the end of the year. Its social media presence, led by an unhinged owl character, became a marketing asset in itself.
Timeline
- 2012
Public launch.
- 2017
Duolingo Plus subscription introduced.
- 2019
Leaderboard leagues added.
- 2021
Nasdaq IPO.
what made it work
- Short, game-like lessons that fit into a few minutes a day.
- Streaks that use loss aversion to keep people coming back.
- A culture of constant A/B testing.
- A distinctive brand character that spread on social media.
the lesson
If your product needs daily effort, design the habit — not just the content.
Apply it to your business
- 1What small daily action would keep your customers engaged?
- 2Show progress and streaks to motivate continuation.
- 3Test changes with real users instead of debating them.
Laws at work in this story
Figures are rounded and drawn from public reports, company filings and widely cited coverage at the time. Check the company's latest filings before relying on any number.