What are some alternatives?
When comparing Codelearn and Hackr.io, you can also consider the following products
Codecademy - Learn the technical skills you need for the job you want. As leaders in online education and learning to code, we’ve taught over 45 million people using a tested curriculum and an interactive learning environment.
Geocities Site Builder - Share your abomination with the world
Famo.us University - Famo.us University includes live coding lessons, tutorials, and discrete examples tied to our...
exercism - Download and solve practice problems in over 30 different languages.
Code.org - Code.org is a non-profit whose goal is to expose all students to computer programming.