CodeHS is an interactive online learning platform offering computer science and programming instruction for schools and individual learners.

CodeHS is focused on spreading access to and knowledge of computer science by offering online instructional materials supported by remote tutors.

In the introductory learning module, students on the site practice computer science concepts and programming skills by giving commands to a dog named Karel.

Keeshin and Galant based CodeHS on their experience as section leaders and teaching assistants for several of Stanford's introductory computer science courses.

[10] This approach is based on the original Karel programming language developed by Richard E. Pattis and is used in Stanford University's introductory computer science classes.