A free summer is the perfect window to actually level up in AI instead of letting the break disappear. These are the five free courses I'd grind, in order, from beginner foundations all the way to the frontier. Pick one, commit to it for a week or two, then move to the next.
The Summer AI Curriculum
Google Machine Learning Crash Course
Google's free, ~15-hour intro to machine learning. It combines animated video explainers, interactive visualizations, and real coding exercises. It was recently updated with full sections on LLMs and generative AI. You earn a badge per module. The best starting point if you want to understand ML properly.
The Hugging Face Course
The best free course for understanding how large language models actually work. You learn NLP and transformers using the Hug Hugging Face ecosystem, and build, fine-tune, and deploy your own models. Essential knowledge given that LLMs power almost every AI product today.
Practical Deep Learning for Coders (fast.ai)
A world-class, completely free deep learning course that's project-first. You train a working model in lesson one instead of grinding theory for months. By the end you can build image classifiers, NLP models, and more, and you genuinely understand what's going on under the hood.
Hugging Face Deep Reinforcement Learning Course
The most fun course on this list. You train autonomous agents to land a lunar lander, play Space Invaders, Doom, and Minecraft using libraries like Stable-Baselines3. It's free, fully hands-on, and you can earn a real certificate of completion by passing 80% of the assignments.
Andrew Ng's Machine Learning Specialization
The most legendary machine learning course online, created by Andrew Ng with DeepLearning.AI and Stanford. It's an updated 3-course version of his original course, taken by 4.8M+ learners and rated 4.9/5. You go from regression, classification, and neural networks to clustering, recommenders, and reinforcement learning, with the clearest explanations anywhere. Beginner-friendly, around 2 months at a relaxed pace, and free to audit (the certificate is paid, with financial aid available).
How I'd Prioritize
Start with the Google ML Crash Course for a fast intro, then go deep with Andrew Ng's Machine Learning Specialization for rock-solid foundations.
From there, the Hugging Face Course and fast.ai get you hands-on with modern transformer and deep learning models, and the Deep RL course is the fun finisher once your basics are solid.
Good luck this summer — and reach out if you have any questions!