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Harvard CS50 in 2023: How to Get a Free Certificate

Harvard’s intro to computer science was just updated! Here’s what’s new and how to earn a free certificate.

Harvard CS50 2023 opening lesson in Harvard’s beautiful Sanders Theater. You might recognize the place. Many movie scenes were filmed there. If you watched Denzel Washington’s The Great Debaters, the final debate takes place inside Sanders Theater. (Photo source)

With its over 4.3 million enrollments, CS50, Harvard’s Introduction to Computer Science, is one of the most popular online courses ever. And it’s one of Class Central‘s Best Online Courses of All Time.

Having taken the course myself, I can’t say I’m surprised. The course is excellent: it has a fantastic instructor; it offers a rich learning experience; and the course content is refreshed every year, on January 1st.

Most notably, the course is entirely free, and it includes a free certificate of completion. But understanding how to obtain it can be a bit confusing. So in this article, let’s discuss CS50 and explain how you can earn a free certificate.

(Harvard also offers other free courses on topics such as Python, web development, and AI. Learn more in our Harvard CS50 guide.)

CS50 Overview

Malan invites students on stage to explain binary numbers in an interactive manner. On the left, you can see the green screen used during live coding sessions. (Photo source)

CS50 is taught by Harvard Professor David J. Malan, who’s also been teaching the course on campus since 2007. Malan is a real showman. Forget dull PowerPoint presentations with monotone voice-overs. Malan takes the stage in Harvard’s beautiful Sanders Theater to enthusiastically teach computer science in front of a live audience.

It’s one of the most striking aspects of the course. It’s really well made. Malan paces the stage while filmed from multiple angles, using props to explain concepts, inviting students on stage for interactive demos, or standing at his laptop in front of a green screen for live coding sessions.

The course production values are off the charts, and Malan’s passion for teaching computer science is palpable. Naturally, this has contributed to the course’s success. Even by campus standards, CS50 stands out. With around 1,000 students enrolled every Fall, CS50 is the largest course on Harvard’s campus.

I think the main strength of the online course is that Malan treats it just like his on-campus course. The online and on-campus courses are one and the same, rather than the former being a lesser version of the latter. Both have the same lectures, same problem sets, and same final project. In terms of learning, it gets really close to the full Harvard experience.

What’s New in 2023

In the new problem Wordle50 (on the right, above), you’ll have the opportunity to implement a program similar to Wordle (left, above), the word-guessing game invented by James Wardle that became a global phenomenon in late 2021 and was acquired by The New York Times in early 2022.

Another strength of CS50 is that the course is updated every year, allowing it to keep up with the latest trends in the field. More specifically, the course is recorded every Fall on campus at Harvard. Then, come January 1st, the online version is updated to use the new recordings. For instance, CS50 2023 uses the recordings made at Harvard in Fall 2022.

In my experience, annual recordings are exceptionally rare in online education. In the vast majority of cases, lectures are recorded once and reused throughout the lifespan of the course. The only other course I can think of that has annual recordings is MIT’s Introduction to Deep Learning. This seems to be a privilege restricted to a few, popular courses at rich institutions.

The annual recordings are also an opportunity for curriculum updates. In 2023, CS50 introduced the following changes among others:

  • Practice Problems: Every week, before tackling the lab and problem set, you’ll now be able to complete optional practice problems to cement your understanding of the week’s lesson. For instance, here are the Week 1 Practice Problems.
  • More Labs: In Week 1, the Population Growth lab, present in 2021 but absent in 2022, has returned. And an entirely new lab, Smiley, has been added to Week 4, where you’ll learn to manipulate images at the pixel level.
  • More Problems: Last but not least, new problems have been added to problem sets. In Week 2, you’ll be able to complete the following new problems:
    • Bulbs, an entry-level problem, where you’ll practice binary encoding.
    • Wordle50, a more challenging problem, where you’ll write a program to play the popular word game Wordle.

Like in previous years, CS50 ends with an open-ended software project ⁠— an opportunity for students to put into practice what they’ve learned throughout the course.

Different Certificate Types

So, you think this course is for you, and you’d like to get started. Great! But before, there’s one thing worth clarifying, because it often confuses learners. CS50 is offered on four platforms, but only one offers a free certificate.

These three platforms offer CS50, but they do not include a free certificate of completion:

  • EdX, which is the platform most people are usually familiar with. On edX, you can audit CS50 for free. However, edX doesn’t offer a free certificate. It only offers a paid verified certificate, which costs $149.
  • Harvard Extension School, which is part of Harvard’s distance education division. Through this school, CS50 doesn’t include a free certificate. Instead, students can take the course for credit and receive a formal transcript, which costs $1980–3100.
  • Harvard Summer School, which is also part of Harvard’s distance education division. Though this school, CS50 doesn’t include a free certificate either. Instead, students can take the course for credit and receive a formal transcript, which costs $3500.

✔️ This platform offers CS50, and it does include a free certificate of completion:

  • Harvard OCW, which is Harvard’s open online course platform. On Harvard OCW, CS50 includes a free certificate of completion, like the one below. Note that the course content is exactly same as on edX, including all the assignments. The only difference is that the free certificate doesn’t involve ID verification.

Finally, to further confuse matters, even when you take the course via Harvard OCW, you’ll be asked to create a free edX account. To be clear, this is just a logistical step that will allow you to submit your assignments. You do not need to buy the edX verified certificate.

How to Get a Free Certificate

CS50 free certificate of completion in 2023. It lists your name and the assignments you passed, and it’s signed by Professor Malan. Note that the certificate includes a verification link at the bottom that also makes it easy to share.

Since its launch, CS50 has maintained a firm stance toward openness through the Harvard OCW platform. In 2023, the course remains entirely free on the platform, including its certificate of completion. Above, you can see how the free certificate looks.

To unlock the certificate, you have to score 70% or more on:

  1. All the labs. There are 10 labs, one per week.
  2. All the problems sets. There are also 10 problems sets, one per week.
  3. The final project, in the last week.

Note that you can resubmit assignments. So if you don’t pass on the first try, no problem. You can try again.

Ready? Here’s where to get started: Harvard CS50 — Week 0: Video Lesson & Problem Set. Then, simply go week by week. Happy learning!

Manoel Cortes Mendez Profile Image

Manoel Cortes Mendez

Software engineer and online graduate student in computer science passionate about education, technology, and their intersection.

Comments 51

  1. Tommy

    I am currently studying Information Technology and I just wanted to know your schedule so that I can be able to catch up with your programs since I am a new comer.

    • Pat Bowden

      This course (like many others) is self-paced. You can join when you are ready. Lecture videos and other course materials can be accessed at any time of the day or night suitable for you.

      • Ibrahim Ahmed

        CS50 is free with certification

    • Damian

      Hi, is the certificate an edX certificate or does it actually indicate it is from Harvard?

      • Manoel Cortes Mendez

        The free certificate looks exactly like the one in the article, but with the actual learner’s name.

  2. Thom

    This course is not free. You have to pay $ 90 / or when You completed the course you earn a certificate?

    • Isaac

      The course itself is free, but you can choose to pay $90 for a certificate at the end from edX if you would like to.

    • Manoel Cortes Mendez

      You can take the course for free via Harvard OpenCourseWare here: https://cs50.harvard.edu/x/2022/

      Upon completion, you’ll earn a free certificate as explained here: https://cs50.harvard.edu/x/2022/certificate/

      • Steve

        Hi Manoel,

        Thank you for your valuable article.
        It surely helps me.
        I’ve logged in to the page you’ve mentioned
        but, can’t find the apply button for Harvard OpenCourseWare.
        It only has
        If interested in a verified certificate from edX, enroll at cs50.edx.org instead.
        Where do I go for free certificate from Harvard?
        Kindly, would you please guide me through.

        • Manoel Cortes Mendez

          You’re on the right site. You can just go week by week, on the sidebar, completing each problem set. These have submission instructions – for instance: https://cs50.harvard.edu/x/2022/psets/0/

          Once you pass all problem sets and final project, you’ll unlock the free certificate.

  3. Siddhi Deshpande

    Do we get a certificate after completing the course for FREE ? Like just a normal certificate which can be linked or is shareable ?

    • Manoel Cortes Mendez

      Yes, as long as you take the course through Harvard OpenCourseWare, you’ll get a free certificate that you can share.

      This is where you can take the course for free: https://cs50.harvard.edu/x/2022/

  4. Aisha

    The price p
    of verified certificate was 90 dollar but why its showing 299 dollar now?

    • Manoel Cortes Mendez

      The current price of an edX verified certificate seems to be $149.

      But note that you can take the course for free and earn a free certificate by taking the course through Harvard OpenCourseWare here: https://cs50.harvard.edu/x/2022/

  5. Nathalie Aigil

    Hi, I’m from Papua New Guinea and I just want to en-quire if I can take to course online as an International student.

    Thank you.

    • Arjun Murthy

      Yes, you can take the course from anywhere in the world.

  6. Dane

    Where to register and what is the enrollment procedure?

    • Manoel Cortes Mendez

      If you want to take the course for free, just start here: https://cs50.harvard.edu/x/2022/

      You’ll submit the problem sets via edX, but you don’t need to pay for the verified certificate.

  7. endeavour shrestha

    The cost of certificate is 90$ but why is it showing 199$ in mine

    • Manoel Cortes Mendez

      The price of a verified certificate seems to have increased. But note that you can take the course for free and earn a free certificate through Harvard OpenCourseWare: https://cs50.harvard.edu/x/2022/

  8. Raphael Folorunsho


  9. Siphokazi

    I am from South Africa. I would like to know if you do take students from South Africa?

    • Manoel Cortes Mendez

      Yes, the course is accessible to learners worldwide.

  10. N. Luiz dos Santos

    Olá tudo bem!
    Seria Possível eu fazer um curso de (blockchain Crypton moedas, e inteligência artificial) com certificado sendo eu estrangeiro, no meu caso (Brasil) ?

    • Manoel Cortes Mendez

      Harvard CS50 não oferece um curso de blockchain. Mas os cursos que eles oferecem, como este curso de ciência da computação acima, estão disponíveis em todo o mundo, inclusive no Brasil.

  11. ReyFam

    I didn’t get that part where you said that the difference between the free version and the paid version, is ID verification?
    Thank you

    • Manoel Cortes Mendez

      The free certificate only requires passing all the assignments. EdX’s paid ID-verified certificate also requires taking a selfie and picture of your ID card.

      • Juoi Woens

        Does this mean that the free certificate will NOT have your name on it?

        • Manoel Cortes Mendez

          The free certificate will have your name on it. It just won’t be ID-verified. On edX, the paid certificate specifically mentions that they’ve verified your identity. The free certificate doesn’t mention that. It’s based on an honor system.

          • Ayodele Samuel Adebayo (unclebigbay)

            Can someone upgrade the free certificate to an ID-verified version later?

          • Manoel Cortes Mendez


            The free and the paid verified certificates are independent. That said, the assignments you complete to get the free certificate are the same you complete to get the paid certificate.

            So if you’ve earned the free certificate, you’ll have completed all the assignments needed to get the verified certificate. You’ll just have to pay for the certificate and resubmit your assignments.

            Just keep in mind that the course is refreshed every year on January 1st, often with assignment changes. So if you want to “upgrade” to a verified certificate, you’ll want to do it in the same year you earned the free certificate. Otherwise, you may have to complete new assignments.

          • Luis

            [[[So if you’ve earned the free certificate, you’ll have completed all the assignments needed to get the verified certificate. You’ll just have to pay for the certificate and resubmit your assignments.

            Just keep in mind that the course is refreshed every year on January 1st, often with assignment changes. So if you want to “upgrade” to a verified certificate, you’ll want to do it in the same year you earned the free certificate. Otherwise, you may have to complete new assignments.]]]

            Do you have to pay for the verified certificate before you start your course on https://www.edx.org/ ? Or you do so at the end?

            **Also, if I were to start now https://cs50.harvard.edu/x/2022/, that means I can upgrade to a verified certificate in 2023 without having to complete the new assignments?

            If I had to complete the ‘new assignments’ (given the course is refreshed every year), that would be only for whatever changed in the new year or I would have to redo the course?

          • Manoel Cortes Mendez


            When taking CS50 on edX, you may upgrade to a verified certificate at any time. Technically, edX courses have an upgrade deadline (https://support.edx.org/hc/en-us/articles/227443947), but on CS50, that deadline is currently Dec 2023, and I think they keep pushing it back as it approaches.

            On Jan 1st 2023, the new version of CS50 will be released. Past that date, you’ll need to complete the 2023 assignments to get a certificate, free or paid.

            If you started the course in 2022 but didn’t finish, you’ll have to re-submit your assignments in 2023. And if new assignments are introduce in 2023, you’ll have to complete those too. Typically, only a one or two assignments change with each annual refresh, so I wouldn’t wait to get started.

            Finally, if you paid for a certificate in 2022, you won’t have to pay again in 2023: you only pay for the certificate once, regardless of when you end up finishing. That said, since this course has no real upgrade deadline, you can just finish the course for free first, and later decide if you want to upgrade to a verified certificate.

  12. Jeffrey Whewhetu

    Thank you sir!!! For sharing this information. I’ve being looking for free certs to add to my resume and you have made my day. From Nigeria

  13. Gert

    Can you re-use this course.

    on EDX it is part of multiple series like

    Associated programs:
    Professional Certificate in Computer Science for Game Development
    Professional Certificate in Computer Science for Web Programming
    Professional Certificate in Computer Science for Artificial Intelligence
    Professional Certificate in Computer Science for Python Programming
    XSeries in CS50’s AP® Computer Science Principles

    Every one of these programs uses CS50. Is it sufficient to take it once, add another course and receive the professional certificate.

    • Manoel Cortes Mendez

      That is my understanding, yes. If you complete CS50 first, then you’d only have to top it up with one extra course to complete each professional certificate. You won’t need to retake CS50.

  14. Naomi Onasanya

    Please what is the difference between the verified certificate and the Professional certificate? Also the EDX. I need some clarifications, please. Thank you.

    • Manoel Cortes Mendez

      “Verified certificates” are certificates that require ID-verification. EdX certificates are verified certificates, so you’ll have to send a copy of your ID card to edX to get your certificate after course completion.

      EdX “Professional Certificates” are a type of microcredential bundling several online courses. If you complete all the courses, you get a dedicated verified certificate for the whole microcredential, and you get individual verified certificates for each course.

      CS50 can be taken individually or as part of several Professional Certificates on edX. In both cases, you’ll have to pay: edX verified certificates are paid certificates.

      If you take the course through Harvard OCW instead of edX, then the certificate is free, but it isn’t ID-verified.

  15. Marwan

    So I get the point that if I take it on both platforms I get to learn the same thing, but what’s exactly the benefit of paying for the extra $150? I don’t get the point of the ID verification, would the free one be unacceptable in some cases or something?

    • Manoel Cortes Mendez

      Supposedly, a verified certificate looks more official, more credible. Personally, I don’t think it makes much of a difference. I think the value is in the learning, and in this case, since the content of both courses is identical, I don’t see a good reason to pay for the verified certificate.

  16. Luke Inze

    I would like to know how to register on the harvard opencourseware, i’ve been to this link https://cs50.harvard.edu/x/2022/ and still there is no where to register but the course video is available there. I would be glad if you could throw more light on how we would register there fro the free certification.

  17. Cynthia

    Manoel, thank you very much for all this valuable info. After I read it all, I can’t help but notice that you are very patient and answer the same questions more than once. Thank you for your patience and hard work here.
    I just read your articles yesterday and I followed the instructions. Since I’d like to submit the course’s problem sets and final project for feedback, I created an edX account, and I read the course started on Thu, Jun 2, 2022. I’m wondering if it’s too late for me to join this year’s course? My major is not related to IT at all. Do you know on average, how long does it take for most people to finish CS50X?

    • Manoel Cortes Mendez

      I don’t know how long it takes on average, but it’s a substantial course. I’d estimate the workload to be 50-100 hours, depending on whether you’re a complete beginner or not.

      The course will be refreshed on Jan 1st. If you start now, your progress will carry forward, but if some problem sets change or new ones are introduced (1 or 2 every year, usually), you’ll have to submit the new versions to get the certificate.

      More info here: https://cs50.harvard.edu/x/2022/faqs/#if-i-dont-finish-the-course-before-31-december-2022-what-will-happen

      Personally, I wouldn’t wait to get started, since most of the progress should carry forward anyway.

      • That guy 11

        If you complete this course is there specific jobs or salaries you can earn after?

        • Manoel Cortes Mendez

          I don’t think so.

          This course is an excellent starting point to learn about computer science. And computer science can, in turn, lead to certain jobs – for instance, in education, research, or software development. But this course alone won’t take you there. You’ll have to do a lot of extra learning for that. It’s just a first step.

          In addition, this is very much an academic course, as opposed to a career-oriented one. If your goal is getting job-ready as quick as possible, there are more suitable courses out there – for instance, courses that focus more on programming.

  18. Nyx

    What is the age required to enter this course?


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