Udemy bills itself as an online learning marketplace, hosting 130,000+ user-created courses on all kinds of topics (including over 2,000 coding-related classes). While some of Udemy’s offerings are paid (costing $20-$200 per course), there are plenty of free coding classes as well, including some shorter Tech 101-type courses that teach code for beginners.
EdX is another leading online-learning platform that is open source instead of for-profit. It was founded by Harvard University and MIT in 2012, so you know that you’ll learn about cutting-edge technologies and theories. Today, edX includes 53 schools. You probably can’t go wrong with the free Introduction to Computer Science from Harvard University.