Show HN: Every number in a tiny GPT, from one forward pass to one step of RLHF https://ift.tt/GJobamW

Show HN: Every number in a tiny GPT, from one forward pass to one step of RLHF Source: https://ift.tt/BdfZNoa Made this with Opus 5.5 to understand the exact working of an LLM. It's a step by step walkthrough of a toy GPT-2 like model. Every matrix fits on screen, every number is computed live in the browser, and hovering over any cell shows the exact math of that step. It covers inference -- following the generation of one token from tokensiation to sampling, one training step of pretraining, and one PPO iteration of RLHF for post-training. Inspired in part by Brendan Bycroft's LLM visualization ( https://ift.tt/veIu4sR ) https://llm.manogya.dev October 7, 2026 at 04:44AM