Harvard University’s CS50 is one of the most popular introductory computer science courses in the world.
We just released a 25-hour CS50 course on the freecodecamp.org YouTube channel. This is the updated version for 2026, with a new section on the impact of artificial intelligence on computer science.
David J. Mullan is widely regarded as one of the best instructors in computer science. He teaches this course.
This course provides an introduction to the intellectual enterprises of computer science and the art of programming. This course teaches students how to think algorithmically and solve problems efficiently.
Topics include abstraction, algorithms, data structures, encapsulation, resource management, security, software engineering, and web programming. Languages ​​include C, Python, and SQL plus HTML, CSS, and JavaScript.
The main goals of this course are to encourage students to explore unfamiliar waters, without fear, to create an intensive, shared experience, accessible to all students, and to build community among students.
The lectures included in this course are:
Lecture 0 – Scratch
Lecture 1 – C
Lecture 2 – Arrays
Lecture 3 – Algorithms
Lecture 4 – Memory
Lecture 5 – Data Structures
Lecture 6 – Python
Lecture 7 – SQL
Artificial intelligence
Lecture 8 – HTML, CSS, JavaScript
Lecture 9 – Flask
Lecture 10 – Emoji
Cybersecurity
View the full course freecodecamp.org YouTube channel (25 hour clock)