Take Harvard’s CS50 online and earn a verified certificate

Start today with CS50, Harvard's introduction to computer science courses. Build skills through engaging lectures, hands-on projects, and a global community of learners.

What are Harvard's CS50 programs?

Harvard's CS50 is a series of online computer science courses taught by Harvard University and available on edX.

Most learners start with CS50x, a beginner-friendly introduction to programming and problem-solving, designed for learners with and without a computer science background. In fact, about two-thirds of CS50 students have never taken a computer science course before.

You can continue with CS50 courses on topics such as Python, AI, cybersecurity, and web development. Each one shares the CS50 name but focuses on developing a different skill set.

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Where to start with CS50

Not sure where to begin? Your starting point depends on your experience and goals.

New to computer science

Start with CS50x, Harvard's introduction to computer science. You'll work through 11 weeks of content, including lectures, problem sets, and a final project, at your own pace. To earn a verified certificate on edX, complete the assignments and final project with a score of at least 70%.

Some technical experience

You can skip CS50x and jump straight into a CS50 course focused on areas like AI, Python, SQL, cybersecurity, web programming, or specialized topics like CS50 for Lawyers or Business. These courses concentrate on a single subject and help you apply computer science concepts in a more targeted way.

Know what you want to focus on

Choose a CS50 Professional Certificate program. These programs bundle CS50x, Harvard's introduction to computer science, with a specialized CS50 course, offering a more structured path to building skills. You can also save 10% when you purchase a Professional Certificate instead of enrolling in courses individually.

Find the right CS50 course for you

How much does Harvard's CS50 cost?

You can start CS50 for free by auditing the course on edX, and upgrade anytime to access the full experience. This lets you explore different topics, choose the right learning path, and upgrade when you're ready to complete graded assignments and earn a verified certificate.

Audit track

Access lectures, readings, and problem sets at no cost. Explore CS50 and build foundational knowledge before upgrading.

Verified certificate

Complete graded assignments and earn a verified certificate from HarvardX. Focus on one course at a time. Typically $50-$300 per course.

Professional Certificate

Follow a structured path with CS50x and a specialized course. Save 10% with a Professional Certificate through the benefits of bundling.

CS50 lecture in Sanders Theatre with Professor David J. Malan, featuring the course’s signature yellow rubber duck mascot.

Why upgrade to a certificate?

Earn a verified HarvardX CS50 certificate with identity verification
Complete graded assignments and projects
Showcase your skills on your résumé or LinkedIn profile
Connect with a global community of CS50 learners and alumni

Explore all CS50 Professional Certificate programs

What you'll learn in Harvard's CS50 programs

More than coding, CS50 teaches you how to think like a programmer. You'll break down problems and design solutions from the ground up, with skills you can apply across programming languages and technologies.

What sets CS50 apart is how you learn. Problem sets draw from fields like the arts, humanities, and sciences, helping you apply computer science concepts in real-world contexts. You can also learn alongside a global community, with support on platforms like Discord, Reddit, and GitHub.

Core computer science concepts

Computational thinking, abstraction, and algorithms
Data structures and database design
How systems communicate through APIs and networks
How to design solutions that scale and perform efficiently

Tools and languages

Programming languages, including Scratch, C, Python, JavaScript, R, and SQL
Web development with HTML, CSS, JavaScript, and frameworks like Django or Flask
Database design and querying with SQL
Development workflows and collaboration using tools like GitHub

Meet your CS50 professors

CS50 stands out for its engaging teaching style, driven by instructors who bring energy and clarity to every lecture.

David J. Malan

Gordon McKay Professor of the Practice of Computer Science at Harvard University and a leading voice behind CS50, known for his dynamic lectures.

Meet David

Brian Yu

Senior Preceptor in Computer Science at Harvard University, recognized for structured explanations across courses in AI and web development.

Meet Brian

Doug Lloyd

Senior Preceptor in Computer Science at Harvard University, focused on practical instruction in courses like CS50x and CS50 for Lawyers.

Meet Doug

Why CS50 matters for your career

A CS50 certificate shows that you can solve problems, write code, and complete projects. Many in-demand jobs across industries and sectors rely on these same skills.

While CS50 alone is not a complete qualification for these roles, it can serve as a strong foundation for further education and experience that can lead to these careers. According to the Bureau of Labor Statistics, roles that build on these skills include:

Student presents their CS50 final project, type50, at the CS50 Fair, an end-of-semester event where projects are demonstrated to the Harvard community.

Computer hardware engineer

Entry-level education: Bachelor's degree
Median annual salary (2024): $155,020
Projected job growth (2024-34): +7%

Computer network architect

Entry-level education: Bachelor's degree
Median annual salary (2024): $130,390
Projected job growth (2024-34): +12%

Database administrator or architect

Entry-level education: Bachelor's degree
Median annual salary (2024): $123,100
Projected job growth (2024-34): +4%

Data scientist

Entry-level education: Bachelor's degree
Median annual salary (2024): $112,590
Projected job growth (2024-34): +34%

Software developer

Entry-level education: Bachelor's degree
Median annual salary (2024): $131,450
Projected job growth (2024-34): +15%

Web developer or digital designer

Entry-level education: Bachelor's degree
Median annual salary (2024): $95,380
Projected job growth (2024-34): +7%

Start Harvard’s CS50 online today

Discover where a path in computer science can take you. Enroll in a Harvard CS50 course or Professional Certificate on edX and earn a verified certificate.

Enroll in a CS50 course

Frequently asked questions about CS50 courses

Is Harvard's CS50 free?

Yes, you can take CS50 courses for free on edX through the audit track. The audit track includes access to lectures, readings, and most assignments. You can upgrade at any time before the course deadline to complete graded work and earn a verified certificate.

Is CS50 worth it?

CS50 is worth it if you want to build a strong foundation in computer science and programming. It focuses on problem-solving, core computer science concepts, and practical projects. The verified certificate can help you showcase your skills to employers or schools.

Is CS50 good for beginners?

Yes, CS50 is designed for learners with and without prior experience. Many students start without a computer science background, though the course can feel challenging due to its pace and depth.

How long does it take to complete CS50?

Most learners complete CS50 courses in about 5-12 weeks, but because edX courses are self-paced, you can adjust your timeline to fit your schedule.

Is CS50 difficult?

CS50 can be challenging, especially for beginners or learners from nontechnical backgrounds, because it introduces complex concepts quickly. However, it's designed for learners with and without prior technical experience and is structured with lectures, problem sets, and community support to help you progress at your own pace.

Why should I enroll in CS50 courses?

You should enroll in CS50 courses to build practical computer science skills through a structured, hands-on learning experience. On edX, you'll learn from Harvard instructors, complete graded assignments, and earn a certificate that validates your progress.

Will I learn coding by taking a CS50 course?

Yes, CS50 courses teach you how to code using languages like C, Python, SQL, and JavaScript. More importantly, they help you understand how programming works so you can continue learning new technologies over time.