raiyanyahya/how-to-train-your-gpt
★ 4,058 stars
Covered in week 2026-W20 · the 2026-05 report
Build a modern LLM from scratch. Every line commented. Explained like we are five.
What how-to-train-your-gpt is
This is a 12-chapter, 7,500+ line interactive textbook that teaches you how to build, train and run a modern language model from absolute scratch. The same family of architecture behind ChatGPT, Claude, LLaMA and Mistral.
From the repository README · read it on GitHub →
Transcript
Andrew Ng's deep learning specialization costs $49 a month on Coursera. This does it free. How to Train Your GPT is an open source tutorial that walks you through building a real LLM from scratch in PyTorch, with every line of code commented and explained like you are five. It covers tokenization, attention mechanisms, and the complete transformer architecture. Over 1,500 developers starred it in just two weeks. Star it if this saved you money.