CS50x: Harvard's free intro to computer science, no experience needed
CS50x is Harvard's introduction to computer science and programming. Its course page says you can take it for free via OpenCourseWare, with or without prior programming experience.
What it is
CS50x is Harvard University's introduction to computer science and programming. The course page says it is for "concentrators and non-concentrators alike, with or without prior programming experience", and that two thirds of CS50 students have never taken a computer science course before. It runs eleven weeks of material. It starts with the C language, moves to Python, then covers SQL, HTML, CSS and JavaScript, and ends with a final project. It is not an AI tool. It is a course, so it takes real time.
Is it free?
Yes. The course page says: "Even if you are not a student at Harvard, you are welcome to 'take' this course for free via this OpenCourseWare." The certificate page says that if you score at least 70% on each problem set and the final project, you are eligible for "a free CS50 Certificate". A separate verified certificate from edX is paid. The FAQ says that is the difference between the two certificates, and that you can get both. We did not find the price of the verified certificate on the CS50 pages, so we do not quote one.
How it works
- Each week you watch a lecture, and the page recommends watching the section and shorts too.
- You submit a problem set for each week and then the final project.
- To submit work for feedback, you need an edX account. The FAQ says registering with edX is required for either certificate, free or verified.
- The FAQ says edX has a "free" or "audit" option that needs no payment. Read edX's questions carefully when you register.
The page also says the lectures have been dubbed into Portuguese and Spanish, and it links to introductions in English, Portuguese and Spanish.
Who it suits
- The FAQ says the courses are "perhaps best suited for learners ages 12 and up", and that younger learners may need a parent's help with sign-ups.
- There are no required prerequisites. The FAQ recommends checking the course map to see if it is right for you.
What to watch out for
- Not an accredited course. The FAQ says the free and verified certificates are not accredited academic offerings from Harvard or its affiliates.
- Honesty rules. The course has an academic honesty policy that says the work you submit must be your own. The page says breaches are "handled harshly".
- A real time commitment. Eleven weeks of material with problem sets. We did not check how many hours it takes.
- Licence. The course materials are under CC BY-NC-SA 4.0, which does not allow commercial use, per its licence page.
Privacy and data
- You need an edX account to submit work. We did not read edX's or CS50's privacy policies, so we cannot say what data they collect.
India
- We saw no region limit on the CS50 pages and no rupee price. We did not check whether edX registration or the free option works the same from India.
Frequently asked questions
Is CS50x free?
Yes, per its course page, through OpenCourseWare. A verified edX certificate is paid.
Do I get a certificate?
The certificate page says a free CS50 Certificate is available if you score at least 70% on every problem set and the final project.
Do I need to know programming first?
No, per the course page.
Sources: CS50x, Certificate, FAQs, Licence, Academic honesty. Checked 18 October 2026.
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