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Generative models · From scratch / 2026

Pixel GPT

Draw half a tiny image. Let a transformer finish the thought. A hands-on comparison of image models I trained from scratch.

Built and trained the models and playgroundLive playground

Learning by building the model

Pixel GPT explores image generation at a scale where you can still see what’s happening. I trained the models from scratch and built a playground to compare them.

A few pixels, three approaches

Draw half of an 8 × 8 sprite, then compare a bigram model, an MLP, and a small transformer completing the rest. The same input makes their different behaviour easy to see. Temperature and seed controls let you experiment and repeat a result.

From sprites to faces

A separate transformer completes the missing half of a 64 × 64 grayscale face. You can compare the generated result with a mirrored baseline and the original image.

The repository includes the training code, saved evaluation results, and the Streamlit application. These are deliberately small experiments in learning structure, rather than a general-purpose image generator.

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