Faithful reimplementation of Karpathy's microGPT that runs entirely in a Web Worker. You pick a dataset (YC startups, baby names, dinosaurs, or upload your own), configure the architecture, and watch the loss curve drop in real-time as it trains. Then generate text from your model. Everything runs client-side - back propagation, attention, the whole training loop. The fun technical constraint was keeping the UI responsive while doing matrix math in JavaScript. Built it as a node-based editor so you can see the data flow from dataset → tokenizer → config → training → generation.Github: https://github.com/jayyvk/trainmyowngpt