Duolingo’s battle for learning in an AI world

Note: Transcripts are automatically generated from episode audio, and are not fully corrected for spelling, grammar, and formatting.

LUIS VON AHN: What kind of world are we going to have? The type of world that I would like to have is a world where people really are bettering themselves. That is one way in which they find meaning in life. Will it be the case that in 10 years we can get a significant fraction of humanity’s population, billions of people actually learning something as opposed to either doomscrolling or just giving up on life because AI can do everything? We got to more than a hundred million active users, but that’s too small of a fraction of humanity.

BOB SAFIAN: That’s Luis von Ahn, CEO and co-founder of Duolingo, the language learning app that crossed a billion dollars in annual revenue last year. Duolingo is known on social media for its slightly unhinged owl mascot, but it was Luis himself who went viral last year over an internal AI memo that sparked intense public controversy. Today, we talk through his tough lessons from that experience and what he’s learned about the limitations of AI since that memo. We also talk about why he’s made a strategic shift in 2026, emphasizing user growth over revenue growth, even though 90% of Duolingo’s users are currently non-paying. Plus, in the spirit of Duo The Owl, we talk about fun as a learning strategy, whether you’re teaching languages, chess or new business ideas. So, let’s get to it. I’m Bob Safian, and this is Rapid Response.

[THEME MUSIC]

I’m Bob Safian. I’m here with Luis von Ahn, CEO and co-founder of Duolingo. Luis, great to have you with us.

VON AHN: I’m very happy to be here. Thank you for having me.

Copy LinkWhy fun and surprise make people stick with learning

SAFIAN: You first hit my radar when I was editor of Fast Company. You helped invent CAPTCHA and then reCAPTCHA, the security word puzzles that became kind of ubiquitous across the web. And then, you launched Duolingo, which is this playful but pragmatic language learning system that really took off, and now it’s crossed a billion dollars in annual revenue last year. Duolingo has always been unexpected. Certainly, your social media campaigns have gotten a lot of attention. How important is the unexpected and playful to what Duolingo does?

VON AHN: Ultimately, it’s pretty important. What we want to do is we want to teach people, and we want to, literally, teach billions of people. Most people will tell you they want to learn something, but what people say and what people do happens to be very different. Certainly, trying to be a fun brand, an unhinged brand, that gets people to learn. And so, our belief about teaching is that it’s really important that we teach you something well, but it’s equally or more important that we keep you entertained while you’re learning, because otherwise, most people just won’t learn all that much.

SAFIAN: A lot of your users are adults, so it’s not just kids that you’re trying to get to be playful. And it’s just important for those of us who are trying to be lifelong learners.

VON AHN: Yeah. A lot of our users are adults. Basically, our users are the whole range from age … They need to know how to read, so age, call it six, seven, to a hundred. When we started Duolingo, there were people that would say, “No, no, no, no. Serious learners are not going to want this, because it has to be serious, et cetera.” We have just never found that making something less fun helps. Whenever we make it more fun, even the people who call themselves serious learners end up doing more.

SAFIAN: The decisions you make about Duolingo, is there ever a distinction between engagement and learning? There are some parts of the tech world where there’s been blowback about emphasizing engagement too much.

VON AHN: They mostly go hand-in-hand, because the most important thing is that people spend the time learning. If you want to learn Spanish and you’re an English speaker, you have to put in about 500 hours. That’s basically it. It’s similar with exercising. Whether you’re doing the elliptical or the treadmill, it probably matters a little bit. But what matters the most is that you’re actually doing it a certain amount of time every day. When people are learning on Duolingo, the setting is a little different than a classroom. In a classroom, I think you can frustrate “users.” In this case, the learner a little more, because they have to be in the classroom, whereas-

SAFIAN: It’s not so easy for them to get up and walk away.

VON AHN: Yeah. Whereas, in Duolingo, we are always one click away from Instagram or TikTok or whatever you want. The level of frustration we can give to users has to be lower than what a classroom does, and that probably makes it so that … We probably are teaching a little less, but we just want to have a lot more time. And so, in the end, it actually ends up being good for learning.

Copy LinkHow to motivate learning in an AI-saturated world

SAFIAN: Right now, a lot of the learning that business people are being forced to do is technological is about AI. I know that that’s not been the focus of what the learning is on Duolingo, but are there things about the way we should be approaching learning about this new technology that you would take away from what you do with Duolingo? It certainly isn’t often framed to us as being fun.

VON AHN: I think the most important thing I would say for learning anything: It doesn’t have to be fun. It just has to be that it keeps people motivated. There are multiple ways to keep people motivated. With Duolingo, we’ve chosen mainly fun. That’s the main thing we’ve chosen, but you don’t have to do that. For example, seeing results keeps people motivated. In the case of learning AI, I would say that’s probably a better motivator of the form. I’m going to learn AI, but the first thing that I’m going to do is make myself a dashboard or a mini-dashboard or something. But I think if you find the right motivation, that helps a lot.

Copy LinkInside Luis von Ahn’s controversial all-hands email about AI

SAFIAN: I have to ask you, because last year at this time you sent out this all-hands email about AI that rattled things a bit. No new hires unless teams showed that AI couldn’t do the job and existing employees assessed on their AI use. It really sparked this blowback on social and the stock price. You’re not unfamiliar with taking risks. Was this a bigger risk than you realized at the time?

VON AHN: Absolutely. I did not think this was going to be controversial, because internally, inside Duolingo, this was not controversial. We started as a technology company. I used to be a computer science professor that actually taught the AI class at Carnegie Mellon University. We’ve always used AI in as much as we can. So internally, this was not controversial at all. Externally, I think I was not very clear, and given how I wrote it and without giving it more context, I opened it up to people thinking that what I was trying to do was to fire a lot of our employees. But that was never the intention. We’ve never done a layoff. We still have never done a layoff. In fact, last year when I sent that memo, we increased our number of employees, not decreased our number of employees. There was that misunderstanding because I think there’s a lot of fear that AI is going to substitute jobs, et cetera, et cetera. The way I see it here is our employees are just way more productive if they use AI. And so, I actually want to hire more people because they can do more.

SAFIAN: It also seemed a little bit like you were sort of forcing people. You weren’t making it playful to learn how to use AI. It was almost like a bludgeon, which I guess wasn’t the intent necessarily either. But I do think it’s something a lot of folks are struggling with. How do you get the people on your team who are more resistant to this new technology to get on board?

VON AHN: Yeah. The good news here is, at Duolingo, we hire a lot of people who are pretty young. We hire a lot of people who are straight out of college. We have just not found a lot of resistance here. Internally, we have this thing we call the golden rule of AI usage, which is you have to use AI for the benefit of our learners. Everything we do with AI should be for the benefit of our learners. For example, if it helps you be more efficient at putting out more features, that’s for the benefit of our learners. If we put out a feature that helps our learners learn better because they’re now, for example, interacting with an AI to practice conversation, that’s for the benefit of our learners. Sometimes that when we use AI, we’re able to save costs, but that is not the goal of our usage of AI. That is an okay thing, but it is not the primary goal. It has to be about helping our learners versus we’re going to use AI to save $10 million. That’s just not all that motivating.

SAFIAN: And I just want to make sure everyone, because there’ve been some reports about you kind of walking back some of the things you said in that memo. You’re clearly still a believer in AI. There’s no doubt from you that sort of this is the direction the business has to continue to go.

VON AHN: I’m a big believer in AI, but it definitely comes with asterisks and learnings. For example, my initial memo said that we were going to evaluate every employee on their usage of AI. I don’t think that was right. Many people came to me and said, “Look, for the job that I’m doing, I’m finding that I’m just using AI for AI’s sake because you’re going to evaluate me on that, but it’s not because I actually think that for this particular thing, we can do it better.” I think, ultimately, in the case of performance reviews, what you should evaluate is how much that particular employee is contributing to the company. It turns out for most of our employees, using AI helps them contribute more to the company. That is true.

However, there may be cases, projects or particular roles where it may just not help all that much. And so saying blanket statement, “We’re going to evaluate you on the usage of AI” was not needed, and so we’ve removed that. The other important thing that I think is important to mention when it comes to AI is that we’re trying to use AI as much as possible, but we really don’t want to decrease quality. For some things, AI is quite ready to do high quality stuff. For some things it’s just not. And so, we’re not going to decrease quality just for the sake of using AI.

SAFIAN: So where are you seeing AI not able to deliver that kind of quality?

VON AHN: In a lot of places, for example, we hire a lot of artists and designers and our app is very high craft on design, et cetera. We’re just not seeing AI get to the level of creativity or the level of polish that our top people have by any means. The other place where I think it’s just not the highest quality, one of the biggest problems I think with AI is that it demos really well. What do I mean by that? It’s just like, “Look, it can write a story,” and if you see one story, you probably wrote a really good story, like the one story they showed you. And my God, it wrote a story. But when you go, and in our case, we may need to write 1000 different stories for people to learn a language.
Then, you’ll find that, I don’t know, 20% of the things were just pure slop. Whenever we scale a lot with things with AI, we have to really be careful that slop doesn’t get through. And if the quality’s just not high enough, even though AI is really nice and that it can do it pretty fast, we just don’t go for it.

SAFIAN: Yeah. I’ve heard some of that with coding too. It can be terrific in writing code and then it can produce stuff that like, “Well, that just doesn’t work,” and you need to dig into that to test all of those uses.

VON AHN: Yeah. For the longest of times, if you would read Twitter, the vibe there was you probably should just fire all your engineers because AI can code way better than any human. That is just not true. Internally, you would see your engineers were all using AI, but somehow you hadn’t seen a speed up in engineering progress. The number of features we put out every month or whatever was just not increasing. When you went to see why that was, you would see that, oh, it turns out in some cases it does something amazing. And then the other cases, just like you said, it kind of doesn’t work, but even worse. It’s so hard to figure out why it didn’t work that you spend about as much time as you saved on the cases that it worked figuring out why the other thing didn’t work. It’s getting a little better because coding agents are getting better. You can find a project with one engineer that maybe was 10 times faster, but overall, this is just not yet true.

Copy LinkWhy Duolingo is prioritizing user growth over profitability

SAFIAN: In 2026, you’ve sort of signaled a strategic shift for Duolingo prioritizing user growth over profitability, which seems like another risk, especially for investors. Why make this move and why now?

VON AHN: I decided that this year we would really spend at trying to work much more on user growth rather than revenue growth. The reason for that is … there’s a number of reasons, but probably the biggest one is I really think that over the next few years, the way most people learn is going to change. AI is just going to allow us to teach significantly better than we have in the past. We’re already seeing it. Our product today, in terms of teaching, is way better than it was four years ago. We do studies to see how well our product is teaching. It’s just getting better every year. I think there’s a huge opportunity in front of us, and because of that, whenever you see that there’s a huge opportunity in front of you, I think what you want to do is just capture as much of the market as possible.

The other thing that happened was that our user growth, particularly towards the end of 2025, did slow. It doesn’t mean that we’re not growing. We’re still growing. We’re still growing exponentially, but it did slow. I sat here and I thought, “Wow! At a time when we should be actually accelerating user growth, it seems to be slightly decelerating. I really don’t like that, so we’re going to make that change.” Now, of course, whenever you go out to the stock market and you say, “This year we are going to lower our estimates for revenue,” the stock market, no likey. We knew this was going to happen, but I really do believe that this is the right thing to do for the long term of the business.

SAFIAN: Just so I’m sure that I and our listeners understand your business model, most of your users are free users already supported by ads that come after a lesson. Most of your revenue is from premium users or premium fees, and so user growth means more emphasis on the free level?

VON AHN: Yeah, that’s the main thing that helps us grow users. About 90% of our monthly active users are not paying us and about 10% pay us. But the amount of money we make is flipped. About 90% of the amount of money we make comes from the 10% that pay us. Most of the money we make comes from subscriptions. Increasing the fraction of people who pay is actually not that hard for us. We can do it at any point in time. If at the end of a lesson I give you one ad versus if I give you two ads, that makes a huge difference in the number of people that pay.

SAFIAN: So it’s not just that you get extra revenue from having two ads, it’s that for me as a user, I’m like, “I don’t want to listen to the ads or want to watch the ads, and I’ll pay.”

VON AHN: And you end up subscribing. Yes, but the thing is, again, we’re trying to be a long-term business, and it does come at a cost, because maybe two ads is not that annoying, but at some point if you’re playing 17 ads at the end of a lesson, people are probably just going to leave.

SAFIAN: Particularly for your users who can’t afford the premium, right?

VON AHN: Correct.

SAFIAN: You’re kind of driving them away.

VON AHN: Correct. That’s why we don’t pull that lever, but it is an easy lever to pull. And again, it’s not just ads. You can do a lot of things.

SAFIAN: Almost every freemium business eventually piles on ads. Netflix did it, YouTube did it. The question isn’t whether Duolingo will pull that lever in 2026 as much as how big it can grow before it has to and what that says about the future of education. We’ll talk about that more after the break. Stay with us.

[AD BREAK]

Before the break, Duolingo’s Luis von Ahn shared his missteps and learnings about AI and why Duolingo is de-emphasizing revenue growth in 2026. Now, we dig into the limits of unhinged marketing, what happens when stakeholders don’t speak the same language, as Luis puts it, and what not to do if you want to get hired at Duolingo. Let’s jump back in.

Copy LinkBalancing unhinged marketing with proof that the product works

As you’re going to try to open up this top of the funnel really, bring more people in, does that mean more of the social media stunts that Duolingo is kind of known for? I’m remembering staging the death of your mascot, the Green Owl Duo, last year. But I also saw something your chief marketing officer said that social output that was 80% unhinged and 20% wholesome that now is going to become more balanced.

VON AHN: Historically, our social media has been an incredible growth lever. Owl mascot has become really popular, and to the point where we don’t have much control over him. Like you said, he staged his own death. But we really do think that it is important to also convey some things in our marketing that I think historically we just have not because it’s actually quite effective. If you go look, it’s about as effective as a classroom. That’s just not something we have really said a lot in our marketing because we spent a lot of our marketing doing stunts, unhinged things, having the owl twerking, which has been successful in its own right. We need to thread the needle here to try to continue being fun, but also move a little more towards having a message that is like, “Hey, you know what? Duolingo actually really works.”

Copy LinkHow Duolingo is expanding beyond languages

SAFIAN: In this user expansion, how much of the plan is around expanding what you teach? I’ve always thought of Duolingo as for languages. But courses on math and music and chess, why did you add those areas? Is your vision of Duolingo’s future to be more expansive?

VON AHN: Yeah. We may not teach everything, but we want to teach the subjects that are meaningful to you that also take a long time to learn. Math is an example. Languages is an example. Music is an example. Chess, even though it’s our newest subject, has gotten the most traction outside of languages.

SAFIAN: Interesting.

VON AHN: Languages, by far, is still the biggest. The other thing that sometimes people in the United States may not understand is just how big language learning is in the world. There’s about two billion people in the world learning English. I don’t know of a subject, including math, that has as many people learning in math. There’s about a billion people learning math. Languages is the largest thing. Chess is the second largest for now for us, but I believe that over time math is going to overtake chess. That’s my hope. At the moment, no numbers support my hope, but that’s my hope.

SAFIAN: As you’re talking, I’m thinking about another digital learning platform, Khan Academy, that rose up alongside Duolingo. I’ve had Sal Khan, the founder and CEO on the show, also an early AI believer, recently teamed up with Ted to offer a degree in AI skills. Will Duolingo become more like Khan Academy in subject range? It’s almost like the two businesses are converging. Do you and Sal ever talk about that?

VON AHN: We do. I know Sal. We do. I don’t know if we’re going to exactly converge. Who we are trying to reach in many case is pretty different. Sal has this incredible videos that explain subjects incredibly well. Our approach is to be more like a mobile game. In some sense, they’re quite complimentary. Khan Academy has been mostly geared towards schools and school usage, et cetera. Whereas, many schools do use us, but we’re really for the whole population.

Copy LinkHow a public company balances users employees and investors

SAFIAN: Khan Academy is also a nonprofit. Duolingo is not. You’re a publicly traded company, worth more than $4.5 billion. You went public in 2021. How has your role as CEO changed since taking Duolingo public?

VON AHN: I would say the first couple of years, it didn’t change all that much, but I think it has changed more recently, especially when I had to say that we were going to have a different strategy. Now, as a publicly-traded company, I have to convince the board, the employees and public market investors, who I don’t have a direct conversation line to. The vast majority of them, they’re just people on the internet. There’s our users, probably the most important constituency, but there’s also our employees. Also, our investors, and they are not really aligned. Maybe in the long term they all are, but certainly, in the short term. Users, what they want is to get the entirety of the learning as good as possible and as free as possible. And again, this is a caricature. But investors just want us to charge every user as much as we can and employees are somewhere in the middle. Employees probably want us to give Duolingo entirely for free, but they also want to make a lot of money.

SAFIAN: They say that you get the investors you deserve. If you talk too much about delivering results today, you get a lot of short term investors. And there’s that issue of, are you in business to make as much money as possible versus having a sort of more social mission? Is teaching people a conduit to making money or is making money a conduit to teaching people?

VON AHN: It’s a really good question, and I may be an incredible optimist, and it may be that I’m wrong, but it is my belief that if you look in the long term, these two are the same, but not in the short term. I agree. In the short term, it really matters which one you’re prioritizing. But I think in the long term, what’s going to matter the most and what’s going to also make the most money is a company that really is putting the education of the users first. I think that will be the larger company in the long term. Now, can I prove that to you? I can’t, but that is my optimistic thinking, that in the long term these two are actually aligned.

SAFIAN: How much of the decision to broaden beyond languages is prompted by new AI tools that enable instant live translation across languages? Do you worry that people won’t be as motivated to learn a language as time goes by?

VON AHN: No. I don’t worry about that. We have two big buckets of users. The first is people who are just hobbyists. If they’re learning language as a hobby, whether a computer can do it or not, doesn’t seem to matter to them. It’s similar to … By the way, we also teach chess. A computer beat the world chess champion in something like 1997. It turns out humans are just not particularly good at playing chess when it comes to computers, which is not. But it’s still the case. There’s millions of people learning chess, because it’s a hobby. Similarly, languages, a big group of our users is a hobby, and I don’t think they’re going to change. And then, the other huge group of our users are people who are learning English either for a job that they want to get or to come study here in the US or in the UK, et cetera.

In that case, they actually need to learn it themselves. It’s an even bigger question, which is some people have said, “Well, with AI, why do you need to learn anything?” It would be a chaotic society if nobody learned anything. People still need to learn stuff. I do think that what people are going to learn is probably going to change some, and I don’t know exactly how. But again, people still do need to learn stuff, including math. They need to learn math just so that they can learn logical thinking.

Copy LinkWhy attention and motivation are the hardest parts of teaching

SAFIAN: You’ve been a professor teaching in a classroom. You’ve now run Duolingo for more than a decade. What do you think people misunderstand about learning, about teaching? What makes it hard? What turns people off? What turns people on?

VON AHN: In my experience, the hardest thing is keeping people motivated. There’s been a technology that teaches any subject really well that has existed for a very long time, which is called a book. A book, you can actually learn almost any subject you want. You can learn quantum physics by just reading books, you can do that. But it just turns out the vast majority of the human population does not have the stamina to do that. That is just not a thing that they would do. I think the hard thing is getting people’s attention, and I do think it’s getting harder and harder, because people’s attention spans are getting shorter and shorter. I think that is the hardest thing about teaching somebody, keeping them engaged.

SAFIAN: And different people can also learn better in different ways. Is that part of the challenge?

VON AHN: It is definitely the case that different people do learn in different ways. We do personalize whenever you start a lesson on Duolingo, it is personalized to you. But I will say, I think that is exaggerated. It is rare that we find changes that only apply for this group of people versus that group of people. You hear these things that are like, “Oh, no, no, no, no,” but people in China are very different. They use apps very differently, or people in whatever. France, very different, et cetera. It’s very rare that you find a feature that works in one country but not in another one. It’s very rare. Typically, most people are pretty similar. For example, if you have a progress bar that you’re filling up and it’s three quarters filled, pretty much every human will want to fill it to 100%. That is just a universal truth. I think there are more universal truths than there are very specific differences between people.

SAFIAN: You are not shy about unconventional ways of approaching things. I was looking at this viral clip of you telling a story that you paid a taxi driver to report on how job candidates treat them during the ride to interviews, which is a particularly tricky way to learn.

VON AHN: A little clarification, by the way, I don’t know how this got … It wasn’t a taxi driver. We would send them a limo driver that works for us. By the way, it’s not like I sat there paying this person. All that happened is that at the end of an interview, we would’ve go asked just this person, “Did they treat you nicely?” And it turned out there was signal in that. In most cases, they were treated nicely. But there were some cases, particularly one case where we were about to make an offer and the person said, “No.” They really were not very nice and we didn’t make an offer. When you’re trying to hire somebody, it’s usually because there’s a hole in the organization that you’re trying to fill. We have this internal rule that we’d rather have a hole than an A-hole. That is what gave rise to that.

Copy LinkDuolingo’s mission to make learning more meaningful than scrolling

SAFIAN: What’s at stake for Duolingo right now?

VON AHN: What we’re trying to achieve, especially because of AI, is what kind of world are we going to have? The type of world that I would like to have is a world where people really are bettering themselves, that is one way in which they find meaning in life, et cetera. Will it be the case that in 10 years we can get a significant fraction of humanity’s population, billions of people actually learning something as opposed to either doomscrolling or just giving up on life, because AI can do everything. What I’m hoping we can do is just add meaning to that many people. At the moment, we have north of a hundred million active users, which is nice. That’s nice. Good job, Luis. We got to more than a hundred million active users, but that’s too small of a fraction of humanity for me to claim victory. I’m hoping that we’ll have billions of people learning meaningful things in 10 years.

SAFIAN: You’re not easy on yourself. A hundred million people, that does deserve a pat on the back. Not enough.

VON AHN: Look, it’s good. If you look at education, it’s unheard of to have something that is teaching more than a hundred million people willingly. That’s kind of unheard of. But still, I just think that there should be a world where really people are spending some amount of their time on the screen doing more meaningful things than scrolling forever. It’s not like I’m against social media companies. I’m not necessarily against them or anything, but it seems not all that meaningful to me.

SAFIAN: Well, Luis, this was great. Thanks for coming on and talking.

VON AHN: Thank you. Excellent questions.

SAFIAN: Luis is an optimist as he says. His bet is that in the long run, AI will deepen our love of learning, not replace it. I hope he’s right. So far, the story is different. Layoffs, hiring freezes, universities pleading with students to write one sentence on their own. But as Luis argues about company values too, the long-term is what matters. We have the agency to impact how the story unfolds on AI from here, if we put in the work, the 500 hours or whatever it takes. AI may be fluent in almost any language, but it can’t replace the learning we get from doing something the hard way. I’m Bob Safian, thanks for listening.