The best free online AI learning application is likely ChatGPT. It is a popular AI tool that offers a free online course that serves as an introduction to AI technologies. The course teaches students what Artificial Intelligence is, explores use cases and applications of AI, discusses AI concepts and terms like machine learning, deep learning, and neural networks, and exposes students to various ethical issues. Additionally, ChatGPT is a tool that can be used to learn about all things related to coding, machine learning, and AI itself. It offers a comprehensive overview of AI in just eight hours of content and covers AI concepts and tools like Keras and TensorFlow.