Andrej Karpathy MicroGPT Visualized

By Pradyumna Chippigiri

February 15, 2026

Sensei Andrej Karpathy released MicroGPT, a 243-line, zero-dependency Python implementation of a complete GPT (training + inference). No PyTorch. No NumPy. Just pure Python and math.

Link to the code is here : andrej-karpathy/microgpt

Also the single page html file with full code is here : microgpt.html

Found this wonderful visualization by Vizuara AI that walks through line by line.

Have not gotten the time to go through it yet, but will be doing that soon. So saving it here.

Credits

All credits to Vizuara AI and Dr. Raj Dandekar and team for the visualization. MicroGPT by Andrej Karpathy.