Duolingo’s battle for learning in an AI world (CEO Luis von Ahn) | Rapid Response

The type of world that I would like to have is a world where people really are bettering themselves, because that is one way in which they find meaning in life. And what's at stake for us is, 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 doom scrolling or just giving up on life because AI can do everything. We got to more than 100 million active users, but that's too small of a fraction of humanity.

I'm very happy to be here. Thank you for having me.

I mean what we want to do is we want to teach people and we want to literally teach billions of people. That's what we want to do. Now learning something is an interesting thing. Most people will tell you they want to learn something. But what people say and what people do happens to be very different. I mean certainly trying to be a fun brand, an unhinged brand, in as much as possible because 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.

Yeah, a lot of our users are adults. I mean, basically our users are the whole range from age, they need to know how to read. So, you know, age, call it six, seven to like 100. When we started Duolingo, there were people that would say, 'No, no, no. Serious learners are not going to want this because it has to be serious, etc.' We have just never found that making something less fun helps. It just helps with everybody. Whenever we make it more fun, even the people who call themselves serious learners end up doing more.

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 kind of have to put in about 500 hours. Like that's basically it. It's kind of similar with exercising. I mean 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. With Duolingo, when people are learning on Duolingo, the setting is a little different than a classroom. In a classroom, I think you can frustrate quote unquote users, in this case, the learner a little more because they kind of have to be in the classroom.

Yeah. Whereas in Duolingo, we are always one click away from Instagram or TikTok or whatever you want. So 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.

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. I mean, for example, seeing results keeps people motivated. So, in the case of learning AI, I would say that's probably a better motivator of the form like I'm going to learn AI, but the first thing that I'm going to do is make myself a dashboard or like a mini dashboard or something. But I think it just if you find the right motivation, that helps a lot.

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 and I used to be a computer science professor that actually taught the AI class at Carnegie Mellon University. So we've always used AI in as much as we can. Internally this was not controversial at all. Externally, I think I was not very clear 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. I mean, 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. So I think there was that misunderstanding because there's a lot of fear that AI is going to substitute jobs etc. But the way I see it here is our employees are just way more productive if they use AI.

Yeah. I mean the good news here is at Duolingo we just hire a lot of people who are pretty young. I mean we hire a lot of people who are straight out of college and 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. Like everything we do with AI should be for the benefit of our learners. So, 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 when we use AI, we're able to save costs, but that is not the goal of our usage of AI. It has to be about helping our learners versus we're going to use AI to save 10 million bucks. That's just not all that motivating.

I'm a big believer in AI but that comes with some, you know, it definitely comes with asterisks and learnings. I mean 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. And 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. So that's kind of one important thing. 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.

In a lot of places. For example, we hire a lot of artists and designers. And our app is very, you know, high craft on design, etc. 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. So what do I mean by that? It's just like look, it can write a story and if you see one story it 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 1,000 different stories for people to learn a language. Then you'll find that like 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. So, we do a lot of things to try to do that. And if the quality is just not high enough, even though AI is really nice in that it can do it pretty fast, we just don't go for it.

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. Forget about engineers. That is just not true. Internally, you would see also that your engineers were all using AI, but somehow you hadn't seen a speed up in engineering progress, like the number of features we put out every month or whatever was just not increasing. And when you went to see why that was, you would see that, oh, it turns out in some cases it does something amazing. And in 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. So, this was a little bit of a paradox that was going on. It's getting a little better because coding agents are getting better. Yeah, you can find a project with one engineer that maybe was 10 times faster, but overall this is just not yet true.

Yeah, at the beginning of the year we decided, I decided that this year we would really spend it trying to work much more on user growth rather than revenue growth. And 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. I mean, AI is just going to allow us to teach significantly better than we have in the past. And 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. So 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. And 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. And that's what happened. 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 but I really do believe that this is the right thing to do for the long term of the business.

Yeah, that's the main thing that helps us grow users. So 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. So about 90% of the amount of money we make comes from the 10% that pay us. So most of the money we make comes from subscriptions. Increasing the fraction of people who pay is actually not that hard for us. And 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.

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.

Correct.

Historically, our social media has been an incredible growth lever. Our 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 our marketing has just mainly been so unhinged. For example, that Duolingo really works. I mean, Duolingo is actually quite effective. If you go look, it's about as effective as a classroom, which I think that's just not something we have really said a lot in our marketing because we spent a lot of our marketing being like, you know, 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.

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. Interesting. Languages by far are still the biggest. And languages, the other thing that may 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 it. Math there's about a billion people learning math. So language 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.

We do. I know Sal. We do. You know I don't know if we're going to exactly converge in subjects and certainly our approach, not only is our approach but also who we are trying to reach in many cases pretty different. I mean Sal has this incredible videos that explain subjects incredibly well. Our approach, we're a mobile app and our approach is to be more like a mobile game. So in some sense they're quite complementary. Khan Academy has been mostly geared towards kind of schools and school usage etc. Whereas, you know, so many schools do use but we're really for the whole population.

I would say the first couple of years it didn't change all that much, but I think 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. And so there's our users, probably the most important constituency, but there's also our employees, also a very important constituency. There's also our investors, also a very important constituency, and they are not really aligned in what they want. Certainly in the short, maybe in the long term they all are but certainly in the short term I mean 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 you 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.

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.

No, I don't worry about that. So we have two big buckets of users. The first is people who are just hobbyists and 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. You know 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. We're just not. But this 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 etc. And 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. I mean, people still need to learn stuff. So 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.

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. I mean, 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. So, 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. But that is I think the hardest thing about teaching somebody, keeping them engaged.

It is definitely the case that different people can learn in different ways. But I would say this and we do personalize whenever you start a lesson in Duolingo. It is personalized to you. But I would 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 but people in China are very different. They use apps very differently or people in whatever France are very different etc. It's very rare that you find a feature that works in one country but not in another one. It's very rare. It typically most people are pretty similar. For example, if you have a progress bar that you're filling up and it's 3/4 filled, pretty much every human will want to fill it to 100%. That is just a universal truth.

A little clarification, by the way, I don't know how this got, it wasn't a taxi driver. We would send them like a limo driver that worked for us. And by the way, it's not like I sat there paying this person. What all that happened is that at the end of an interview, we would go ask just this person, did they treat you nicely? And it turned out there was signaling 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.

I think what's at stake 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 because that is one way in which they find meaning in life. And what's at stake for us is 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 doom scrolling or just giving up on life because AI can do everything. What I'm hoping we can do is just add meaning to that, that many people, billions of people. At the moment we have north of 100 million active users which is nice. That's nice. Good job Luis. We got to more than 100 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.

Not enough. Yeah. I mean, look, it's good. And, you know, especially if you look at education, it's unheard of to have something that is teaching more than 100 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 like it seems kind of not all that meaningful to me.

Thank you. Excellent questions.