Deep Dive into LLMs like ChatGPT

This is a general audience deep dive into the Large Language Model (LLM) AI technology that powers ChatGPT and related products. It is covers the full training stack of how the models are developed, along with mental models of how to think about their "psychology", and how to get the best use them in practical applications. I have one "Intro to LLMs" video already from ~year ago, but that is just a re-recording of a random talk, so I wanted to loop around and do a lot more comprehensive version. Instructor Andrej was a founding member at OpenAI (2015) and then Sr. Director of AI at Tesla (2017-2022), and is now a founder at Eureka Labs, which is building an AI-native school. His goal in this video is to raise knowledge and understanding of the state of the art in AI, and empower people to effectively use the latest and greatest in their work. Find more at https://karpathy.ai/ and https://x.com/karpathy Chapters 00:00:00 introduction 00:01:00 pretraining data (internet) 00:07:47 tokenization 00:14:27 neural network I/O 00:20:11 neural network internals 00:26:01 inference 00:31:09 GPT-2: training and inference 00:42:52 Llama 3.1 base model inference 00:59:23 pretraining to post-training 01:01:06 post-training data (conversations) 01:20:32 hallucinations, tool use, knowledge/working memory 01:41:46 knowledge of self 01:46:56 models need tokens to think 02:01:11 tokenization revisited: models struggle with spelling 02:04:53 jagged intelligence 02:07:28 supervised finetuning to reinforcement learning 02:14:42 reinforcement learning 02:27:47 DeepSeek-R1 02:42:07 AlphaGo 02:48:26 reinforcement learning from human feedback (RLHF) 03:09:39 preview of things to come 03:15:15 keeping track of LLMs 03:18:34 where to find LLMs 03:21:46 grand summary Links - ChatGPT https://chatgpt.com/ - FineWeb (pretraining dataset): https://huggingface.co/spaces/HuggingFaceFW/blogpost-fineweb-v1 - Tiktokenizer: https://tiktokenizer.vercel.app/ - Transformer Neural Net 3D visualizer: https://bbycroft.net/llm - llm.c Let's Reproduce GPT-2 https://github.com/karpathy/llm.c/discussions/677 - Llama 3 paper from Meta: https://arxiv.org/abs/2407.21783 - Hyperbolic, for inference of base model: https://app.hyperbolic.xyz/ - InstructGPT paper on SFT: https://arxiv.org/abs/2203.02155 - HuggingFace inference playground: https://huggingface.co/spaces/huggingface/inference-playground - DeepSeek-R1 paper: https://arxiv.org/abs/2501.12948 - TogetherAI Playground for open model inference: https:/