Does duolingo use AI?
Yes, extensively. Duolingo partnered with OpenAI to launch Duolingo Max on March 14, 2023, using GPT-4 to power Roleplay (conversation practice with AI feedback) and Video Call with Lily, a real-time spoken conversation partner that remembers past calls. Max is available in 188 countries on iOS and Android.
Why — the first-principles explanation
Duolingo used AI long before it was fashionable, and understanding the two different jobs it does explains the whole product.
The first job is choosing what to show you, and it's been running quietly for years. Language learning is fundamentally a scheduling problem: a word you learned Tuesday will fade by Friday unless it's reviewed, but reviewing it too early wastes the session. The optimal moment to test you is right when you're about to forget — and that moment differs per word, per person. That's a prediction problem, and a model can estimate it from your history far better than a fixed schedule can. This is unglamorous machine learning that decides which exercise appears next, and it's the reason the app feels like it knows you.
The second job arrived with generative AI, and it targets the thing Duolingo was historically worst at: actually speaking. Tapping word tiles teaches you vocabulary and grammar patterns. It does not teach you to hold a conversation, because conversation requires responding in real time to something unpredictable that a person just said. Duolingo couldn't fabricate that with pre-written exercises — every branch would have to be authored in advance, and real conversation branches infinitely.
A language model solves this precisely because it's a next-word predictor with no script. Duolingo spent months working with OpenAI, then launched Duolingo Max on March 14, 2023 with two GPT-4-powered features. Roleplay puts you in real-world scenarios with app characters and gives AI feedback on the accuracy and complexity of your responses. Video Call with Lily goes further: real-time spoken conversation where, in Duolingo's words, "Lily responds in real time to keep the conversation going—and she'll remember what you discussed the next time you call." You get a transcript afterward to review.
That memory detail is the tell. It's not a chatbot demo — it's an attempt to simulate a relationship with a tutor, the thing that makes human practice work. Coverage as of launch reflects the difficulty: English speakers learning Spanish, French, German, Italian, and Portuguese get both features; Japanese, Korean, and Chinese learners get Video Call only.
The honest limitation: an infinitely patient conversation partner who never judges you is enormously valuable for the beginner's real bottleneck, which is embarrassment. But it also never gets confused by your accent, never gets bored, and never needs anything from you — and real conversation is partly about those frictions.
An example that makes it click
Think about learning to swim from a book versus getting in the pool. The book teaches you the stroke: arm here, breathe there, kick like this. You can ace a written test on swimming and still sink, because water doesn't behave the way a diagram does. It splashes, you panic, your timing falls apart.
Tapping word tiles is the book. It genuinely works — that's how you learn what the words are. But then someone in Madrid asks you a real question at real speed and you freeze, because you've never been in the water.
Video Call with Lily is a shallow pool with nobody watching. Lily talks back at real speed, doesn't sigh when you stumble, and remembers what you talked about last time. It's not the ocean. But you can't learn to swim by reading, and you can't learn to talk by tapping.
Key facts
- Duolingo partnered with OpenAI and spent months collaborating to refine and test GPT-4 before launch.
- Duolingo Max launched March 14, 2023 as a premium tier, available in 188 countries on iOS and Android.
- Duolingo Max includes all Super Duolingo benefits (unlimited energy, no ads, personalized review) plus GPT-4-powered features.
- Roleplay lets learners practice real-world scenarios with app characters and gives AI-powered feedback on the accuracy and complexity of their responses, plus tips for future conversations.
- Video Call with Lily provides real-time spoken conversation in the target language; per Duolingo, 'Lily responds in real time to keep the conversation going—and she'll remember what you discussed the next time you call.' Users get transcripts afterward.
- At launch, English speakers learning Spanish, French, German, Italian, and Portuguese could access both Video Call and Roleplay; Japanese, Korean, and Chinese learners could use Video Call only.
▶ The 60-second explainer (script)
Does Duolingo use AI? Yes — and it's doing two completely different jobs. The first one has been running quietly for years: deciding what to show you next. Language learning is really a scheduling problem. A word you learned Tuesday fades by Friday unless you review it — but review it too early and you've wasted the session. The best moment to test you is right when you're about to forget, and that moment is different for every word and every person. That's a prediction problem. A model estimates it from your history far better than any fixed schedule could. It's unglamorous, and it's why the app feels like it knows you. The second job is generative AI, and it targets what Duolingo was historically worst at: actually speaking. Tapping word tiles teaches vocabulary and grammar. It doesn't teach conversation, because conversation means responding in real time to something unpredictable a person just said. You can't pre-write that — every branch would have to be authored in advance, and real conversation branches infinitely. Which is exactly what a language model is good at, because it has no script. Duolingo worked with OpenAI for months, then launched Duolingo Max on March 14, 2023, with two GPT-4 features. Roleplay puts you in real-world scenarios with app characters and gives feedback on the accuracy and complexity of what you said. And Video Call with Lily is real-time spoken conversation — and here's the tell — Lily remembers what you discussed the next time you call. That's not a chatbot demo. That's trying to simulate a relationship with a tutor. Think of it like swimming. Word tiles are the book: arm here, breathe there. You can ace the written test and still sink. Lily is a shallow pool with nobody watching. And the honest catch — a partner who never judges you fixes the beginner's real bottleneck, which is embarrassment. But she also never gets bored and never needs anything from you. Real conversation is partly those frictions.
What authoritative sources say
People also ask
Is Duolingo's AI free?
The exercise-scheduling machine learning runs for everyone. The GPT-4 features — Roleplay and Video Call with Lily — require Duolingo Max, the premium tier launched March 14, 2023.
What model does Duolingo use?
Duolingo Max's conversation features were built on OpenAI's GPT-4, after months of collaboration between the two companies to refine and test the technology before launch.
Which languages have the AI conversation features?
At launch, English speakers learning Spanish, French, German, Italian, and Portuguese got both Video Call and Roleplay. Japanese, Korean, and Chinese learners got Video Call only.
Can talking to Lily replace a human tutor?
It fixes the beginner's biggest bottleneck — embarrassment — by giving you an infinitely patient partner. But it never gets confused by your accent, never gets bored, and never needs anything from you, and real conversation includes those frictions.
Does Lily actually remember our conversations?
Yes — Duolingo says she'll remember what you discussed the next time you call, and you get a transcript afterward to review. That continuity is meant to simulate an ongoing tutor relationship.