Simon Willison’s Weblog

nanoGPT. “The simplest, fastest repository for training/finetuning medium-sized GPTs”—by Andrej Karpathy, in about 600 lines of Python.

Posted 2nd January 2023 at 11:27 pm

Recent articles

Gemini 3 Flash - 17th December 2025
I ported JustHTML from Python to JavaScript with Codex CLI and GPT-5.2 in 4.5 hours - 15th December 2025
JustHTML is a fascinating example of vibe engineering in action - 14th December 2025

python 1216 ai 1742 gpt-3 67 andrej-karpathy 34 generative-ai 1539 llms 1503

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