How does Duolingo decide which courses to add next?

From the series Ask us about Duolingo, Round 1!

Most Voted For Question: 149 Votes

How does Duolingo decide which courses to add next?

Thanks for the excellent question _ Goldens _ (and to hughcparker, IsakNygren1, and otsogutxi, who asked similar questions)!


Every time Duolingo considers a new language, we ask ourselves 3 important questions:

  1. How many people will benefit from this course?
  2. Can we support the tools and infrastructure necessary for this course to succeed?
  3. Who will create the content, handle reports, and moderate the forums to help learners?

Number of potential learners - our mission is to make education accessible to as many people as possible. This is why we first consider the number of people who want to learn a language and why the first Duolingo courses included Spanish, English, Portuguese, French and German. Duolingo currently spends most of its efforts improving existing courses and optimizing the course creation process because, as good as the courses are, we believe that we can make them even more effective. Focusing on course quality first and foremost will benefit existing courses as well as potential courses created down the line.

Technical cost - every course requires lots of resources to build and maintain so we have to pick carefully. Our tools and features are easier to modify for some languages than others. For example, languages with certain alphabets and special characters unfortunately cost us more to create and will take longer to integrate with the Duolingo system. (Yes, we hope to be able to teach Japanese and Mandarin some day! Until then, check out Tinycards, the Duolingo companion app which features tons of helpful flashcard decks to get you started learning languages and scripts that are still beyond Duolingo’s course offering.)

Contributors - qualified volunteers are a prerequisite to creating each course. Duolingo’s contributors generously donate time and expertise to create and maintain the content that allows millions of people around the world to learn for free! We are thankful for each one of the thousands of contributor applications and are working on tools that will help even more of you give back.

NOTE: Some courses may seem like exceptions to these criteria. We’re well aware that there are excellent arguments for certain courses and that we won’t be able to please everyone. But sometimes the stars align and we’re able to create courses like High Valyrian. Why? Because! Part of what makes Duolingo great is that we are a diverse, open minded (and yes, imperfect) bunch. And a launch of a course such as High Valyrian is not the reason we have not launched Mandarin. Duolingo reserves the right to throw in a curve ball from time to time and admit it, you wouldn’t have us any other way :)

November 10, 2016


So if we assume Arabic fails point 2, what's holding Finnish and Latin back? They are 2 of the three most requested courses (according to the voting you have specifically asked us to do), they don't have different alphabets or characters, they don't have unique features other languages already here don't have and dozens of people have applied to contribute.

November 10, 2016

Seconded on the Finnish, it's one of the most highly requested languages, there are known applicants to contribute, and there are already agglutinative languages on the platform. What's holding it back?

November 11, 2016

Exactly! Hungarian has a similar structure to how a Finnish course could be built but apparently the staff think that Klingon is a "great" alternative :I

November 12, 2016

Why are you learning 22 languages simultaneously?

August 22, 2018

Yes, I see absolutely no reason to make a Hungarian course but not a Finnish course (do not get me wrong, both are great languages in my opinion but from what I understand, Finnish is slightly simpler than Hungarian and is more useful to several groups of people such as those interested in the Nordic culture or Lutherans who wish to study in Finland).

November 7, 2017

Same question for Tagalog-for-English. A lot of people want to learn Tagalog (and Cebuano) and many people have offered to help create the course.

November 11, 2016

They have started the English for Tagalog course. That means that Tagalog for English will be likely to enter the Incubator once the English course is completed.

November 11, 2016

I want Latin! (This is so I will be ahead in class at school)

August 24, 2018

Looks like you have about a year to wait. The estimated completion date on the Latin for English course is currently January 7, 2020. The course has 17 contributors, so it might be finished ahead of schedule.

January 28, 2019

I noticed there is not even one dead language in Duolingo that I have seen, is there any rule against building courses designed to teach languages without any native speakers?

November 7, 2017

No, there is no rule against any particular class of languages. (I prefer to say "ancient" rather than "dead" language; it sounds more positiv; also, Latin never really died out, it evolved into its descendant Romance languages, just as Ancient Greek became Modern Greek, and Old English became Modern English.) In fact, there are three constructed languages on Duolingo: High Valyrian, Klingon, and Esperanto. (For multiple reasons, i myself am not a fan of Esperanto.)

January 29, 2019

The number of potential learners. Polls are inaccurate and can sometimes not be representative... seeing how The Donald was elected

November 12, 2016

So how do they determine which has the greatest potential without asking from people? Finnish and Latin (together with Mandarin, Japanese and Arabic) are on top on basically every single poll, they are the most talked about languages that aren't here, they are the most upvoted posts (which they have asked us to do) and they are the easiest languages to implement out of the seven Memrise top 20 languages we don't have (the five I mentioned plus ASL and Thai). For the record, languages like Greek and Norwegian aren't in Memrise top 20.

November 12, 2016

Not in memrise top 20? Not a big deal. There are currently 32 languages offered to English speakers (not counting ones in Incubator), so inevitably at least two will not even be among the memrise top 30.

February 13, 2019

"But sometimes the stars align and we’re able to create courses like High Valyrian. Why? Because!"

I'm sorry but that's not an explanation. The language isn't fully developed, it has no community, there are few people interested in learning it and the language is barely used, even on the TV show. It fails the above criteria, so I simply don't understand how and why it was chosen.

November 11, 2016

Yes! The developer said that he has to make up words for the course! This is unacceptable

November 13, 2016

You never do things just because you want to?

November 11, 2016

Not at work

November 14, 2016

Not when serving in an official capacity.

November 7, 2017

You don't add languages like finnish (widely wanted) or lithuanian (most archaic indo-european language), and add klingon (useless conlang) instead, yet you guys are boasting about how you're "considering how many people will learn the language" and if it's "useful". Come on.

November 15, 2016

I may be a Ukrainian contributor, but I'm gonna be direct. Ukrainian is not the most useful language to learn, it never was. I have my own reasons for learning this language and I'm not denying that I've loved being part of a community that has the same love for this unique language as I do. But, let's face it. Ukrainian didn't do too well on point one, yet they'd rather make a course that not that many people actually want but something like Klingon or Dothraki will get them more likes Facebook, Twitter etc. and make people think cool. Sure it's a smart business move, but think about all the dedicated fans of Duolingo who have been loyal and helpful to the site! Think of all the people who spend their days learning Hungarian as a substitute to Finnish. Think of all the people who post comments asking why they can't learn Arabic and all they get is "We currently are not looking into this but we will look into it in the future" followed by a series downvotes until their post is deleted and their opinions censored.

Listen, the Duolingo staff are very nice people. They've been insanely helpful! They've brought into the incubator, answered many of my questions and overall been some of the kindest people I have ever met. But please listen to the people who've built your courses, tried to convince their friends to join and overall been loyal to your site over the years.

November 12, 2016

I am sure Finnish meets all the criteria, multiple volunteers, there's a facebook group where people are already creating the material, it is one of the most requested languages. Whilst the Valyrian thing might be cute and will probably get publicity and traffic, but even Emilia Clark says sometimes she makes it up when in character.

November 17, 2016
  • 1145

Don't you have a 'pre-incubator' board showing publicly how many people (or who) volunteered to contribute to a new course? I believe that if a course has at least five would-be contributors, it's worth to consider its creation.

January 29, 2018

May I suggest that the next curve ball be something that we actually ask for?

November 11, 2016

Okay but scottish gaelic is starting to die off. I would really like more people to learn it as it was a big part back then. My family still speak it and I do to. I wanted to contribute since it was my first language and I saw the hori We on the amount of people who wanted to learn it

December 22, 2017


December 11, 2018

"you wouldn’t have us any other way"

I would, say if you had thrown in Cherokee instead.

November 10, 2016

When you throw in a curve ball existing of a small - but real world - endangered language, I will thrill:)

November 10, 2016

I'm still waiting for the day Scottish Gaelic's blue and white flag rolls in :)

November 15, 2016

Same, I can even contribute to that course... but no — Klingon and High Valerian take first place. Nothing against Duo,, I simply do not understand why it has been two years and there is STILL not a Scottish Gaelic course in the incubator — there are definitely people that can (and will) help make it possible, and even more people who will take the language and benefit from it. Similar story for Latin.

December 11, 2018

Cherokee for the win!

December 21, 2016

I live in Wales, I speak Welsh, it's a dying language unfortunately only 500,000 native speakers, thankfully there are 344,000 learning on Duolingo.

October 8, 2018

Not exactly a "dying" language; Welsh is currently doing too well to be called "dying". "Vulnerable" language, more like.

February 13, 2019

Would love to see some Konkani, haha

December 16, 2017

I'm surprised at the lack of Mandarin. Would also love to see Hawaiian and Serbian.

February 2, 2017

They need to add Hawaiian!

September 26, 2017

I get that, but I think more people would request Mandarin, Japanese, or Finnish that bloody Klingon... That seems kinda ridiculous to me...

November 18, 2016

So, is there a chance Finnish from English will be added soon? I looked up on the discussions and there's over 3600 results of people who would either like to learn or contribute to the course.

June 3, 2018

Love this website like alot, but I am dissapointed that you have norweigen and swedish, but not finnish or icelandic, which would (especially icelandic) be widely used and loved

November 17, 2016

It could be the frosting on the cake if you add Persian to Duo, so many people are waiting for the course to begin.

September 3, 2018

waiting for years...

October 11, 2018

Can you please add Serbian, because four other countries on Balkan (Kosovo of course isn't one of them! ) understand it well and thrust me everyone here wants to learn another language even those languages that aren't listed here. So please add it because you would be doing a favor to the whole world, giving people the chance to understand a great language that is used in a lot of big countries, because it is written as it is spoken. Those can be yours and the worlds benefits.

January 12, 2017

Yes, Serbian!

February 2, 2017

Yes second that opinion, I would love to learn Serbian in the far future and I think many more people would like to learn at least one south Slavic language.

November 7, 2017

My first language was scottish gaelic and I have contributed for scottish gaelic. Other people wanted it up there but yeah...

December 22, 2017


December 11, 2018

Discussion for the Georgian[1] language had more than 700 votes, but there are gone and we had to start from 0 (50+ now).

When is Duolingo going to fix this bug and bring back our votes? I have reported[2] it 2 months ago, no response.

How can we be sure that this will not happen again? It's very frustrating.



February 24, 2018

So I hope soon Farsi will be added to Duolingo, as you can see here, there are lots of people who want it to be added. Hope you take this into consideration ASAP...

August 3, 2018

I'm ready to contribute ...

October 25, 2018

I have also been ready to contribute since forever...

July 13, 2019


November 11, 2016

Elen sila lumen omentielvo ( a star shines on the hour of our meeting) :)

August 30, 2017

The first point is important. But you should also consider the reasons why people learn languages. Some start for a fun and others learn it for a reason.

I am Armenian. I live in Armenia and 3M Armenians do so, but majority of Armenians (9M of them) live outside of Armenia and they usually try to keep the language so they are having harsh time finding Armenian schools or Armenian after class lessons. They speak Armenian in their houses but by each generation it becomes harder. I believe having an Armenian course in Duolingo will boost they learning curve and it will be really popular abroad. Basically there are Armenians everywhere (Think of it you probably know some of them).

July 8, 2019

That's quite interesting. It is pretty much exactly the same with Afrikaans. Replace "Armenian" with Afrikaans in your comment, and it'll be completely correct.

Anyway, I'm amazed how many Armenians are outside of Armenia compared to how many are inside.

Enjoy your day!

July 8, 2019

WoW never thought that way but now thinking about I assume you are right. And tha's why we should have more courses for Afrikaans and Armenian !:)

July 8, 2019

It's a little disappointing that we're getting ❤❤❤❤❤❤❤❤ like Klingon and Valyrian before more useful or interesting languages, or endangered languages. Very sad!

September 5, 2017

So is it the point two which is stopping Bengali course? But how will it cost more to Duolingo? Dozens and dozens have applied for the course. Few dozens also want to learn It and some even joined Duolingo just for it. The Bengali Academy had made the compound scripts as simple as putting diacritic marks on Latin vowels. Will anyone please tell me, how to do a course request? I am not talking about Applying as I have done it already :(

April 23, 2018

I'd love to see (Westerlauwers) Frisian one day! It's one of (if not) the closest language(s) to English! It's currently endangered, level 4 (5-safe, 1-extinct) and I think a course on duolingo could help making this go a little slower. I think it's a rather interesting language, because it's so familiar and yet so unintelligible when spoken (to me at least). It even has it's own word for the non-matching crockery, it risselreauke. If it becomes available, I'm sure there is a bit of interest for it

June 25, 2018

Hmmm… That's cool

August 24, 2018

It would be great to see a ranking to see how close specific languages are to being added!

April 2, 2019

I agree!

April 2, 2019

Thank you for the answer. But I wonder why Arabic for English speakers can't exist for the moment, but English for Arabic speakers does in fact exist already. That doesn't make any sense to me.

November 11, 2016

I think this post should be stickied.

September 3, 2017

Please put Tagalog! I want to learn it so bad

December 2, 2017

Duolingo needs to add ALL OF THEM.

August 6, 2018

I cannot wait to have Lingala on Duolingo.

November 9, 2018

[deactivated user]

    I like conlang courses on duolingo. Can I create c a course for another conlangs by David J Peterspn? (see or

    November 25, 2018

    [deactivated user]

      I think duolingo should exclude number 2. Minor languages should be included.

      November 27, 2018

      Point 2 is: Can we support the tools and infrastructure necessary for this course to succeed? Have I misunderstood what you are referring to or are you seriously suggesting that Duolingo should add courses without considering whether it has the resources to create and maintain them?

      November 27, 2018

      I hav a challenge for Duolingo.

      The world’s 14 largest languages, by number of nativ speakers, are probably, as of c. 2018 (#nativ speakers, in millions; very approximate):

      1. Chinese (Mandarin), 1000

      2. Hindi-Urdu, 500

      3. Spanish, 450

      4. English, 400

      5. Arabic, 300

      6. Bengali, 250

      7. Portuguese, 200

      8. Russian, 160

      9. Japanese, 125

      10. Punjabi, 120

      11. Javanese, 100

      12. German, 95

      13. Vietnamese, 90

      14. French, 88

      I challenge Duolingo to completely connect these 14 languages; i.e. speakers of every one of these languages would hav, for them, courses teaching every one of the other 13 languages. (E.g. there would be a course teaching German for Japanese speakers, and vice versa; and Russian for Punjabi speakers and vice versa.) This would require 14×13 = 182 different language courses. (Basic combinatorics.) Actually, let’s expand this list of languages to be completely connected with four more members: Italian, Turkish, Korean, and Indonesian. That would require 18×17 = 306 different courses. Now we’re really talking connecting the world!

      What particularly bothers me is that while a number of courses hav been developed that teach a language other than English, to speakers of a language other than English, not a single one of those courses teaches Mandarin Chinese, even tho’ it’s the world’s biggest language. We need to work hard to develop such courses! I myself am even advocating a Duolingo course teaching Chinese for Finnish speakers. (I speak Finnish in addition to English.)


      Tengo un desafío para Duolingo.

      Los 14 idiomas mas grandes en el mundo, por número de hablantes nativos, probablemente son (número de hablantes nativos, en millones, muy aproximada):

      1. chino (mandarín), 1000

      2. hindi-urdu, 500

      3. español, 450

      4. inglés, 400

      5. árabe, 300

      6. bengalí, 250

      7. portugués, 200

      8. ruso, 160

      9. japonés, 125

      10. panyabí, 120

      11. javanés, 100

      12. alemán, 95

      13. vietnamita, 90

      14. francés, 88

      Desafío Duolingo a conectar completamente estes catorce lenguas; es decir, hablantes de cualquier de estes idioma tendrían, por su propio lengua, lecciones enseñando todos los otro trece idiomas. (Por ejemplo, habría una lección de alemán para hablantes de japonés, y viceversa; y ruso para hablantes de panyabí y viceversa.) Este necesitaría 14×13 = 182 cursos distintos. (Combinatoria básica.) Verdaderamente, crezcamos este lista de idiomas que debríamos completamente conectar, con cuatro otros: italiano, turqués, coreano, y indonesio. Este necesitaría 18×17 = 306 cursos distintos. ¡Ahora verdaderamente conectaremos el mundo!

      Lo que especialmente me molesta, es que, hay muchos cursos Duolingo que enseñan un idioma otro que inglés, para hablantes de un idioma otro que inglés; ningún de estes lecciones enseña chino; aunque es el idioma más grande en el mundo. ¡Debríamos verdaderamenta trabajar duro par crear estes cursos de chino! Yo hasta abogo un curso de chino en Duolingo para hablantes de finlandés. (Yo hablo finlandés e inglés.)

      December 8, 2018

      You have the right idea!

      December 11, 2018

      It would be nice, but I don't see this happening anytime in the near future. At least, not for free. DuoLingo currently has 103 courses, including those in development, 63 of which fit your criteria above. That means they would have to add another 243 courses, so they would have to triple their current course-related resources, e.g. more servers and the required floor space and IT personnel, etc.

      By the way, while Chinese is currently only taught from English, and only English and Spanish are taught from Chinese, another five languages are blazing through the incubator for Chinese speakers: German, French, Italian, Korean and Japanese. With any luck, there will be reciprocal trees before long.

      January 29, 2019

      Yes, the top-14-plus-4-more idea is pretty ambitious. However, even if we limit it to top-10, that will still go along way toward connecting the global community, and it will take only 90 courses, some already in existence. That is 13 fewer than the current total number on Duo, incl. those in Incubator, so i think completely connecting the top 10 should be feasible. (Completely connecting the top 14 is iffier.)

      As for requiring an expansion of Duo's floorspace, staff, etc., i suggest decentralization: the numerous additional courses would be developed by contributors (volunteers), all around the world, without putting much extra demand on Duo headquarters. As for finding volunteers (e.g. people who know both Spanish and Punjabi, might be hard to find); speakers of either language, who want to connect the two, could teach themselvs the other language so that they can contribute to said Duo course.

      February 13, 2019

      Volunteers! What a novel idea!

      February 14, 2019

      We want THAI

      February 13, 2019

      Many of my friends and I were determined to start Persian (Farsi) on Duolingo. No success. I am deeply disappointed in this polatform. I have nothing against having non-existant languages on Duolingo but when you put the criteria as mentioned in this post, it is kind of offensive to think that languages like High Valyrian can cut the bar when real languages with rich history and literature behind it fall in the abyss in Duolingo's priority list. Such a shame...

      July 13, 2019

      and if you would like to know whether Farsi satisfies your criteria, look at this post please:

      July 13, 2019
      Learn a language in just 5 minutes a day. For free.