Preparing the model…
Runs in your browser · nothing to install

Watch a machine guess the next word

That is all a language model ever does: guess one word, add it, guess again. Type the start of a sentence, then open this small one up and see every step behind the guess.

Or try

Livechanges as you type

Preparing the model…

Odds for the next word

Press Run, and your sentence goes through twelve steps

    Things to try

    The model has read thousands of short sentences and knows a few thousand words. This is the sort of thing it picked up. In grey: what it answers.

    What you are looking at

    A teaching model, not a product. Here is exactly how far it goes.

    01

    The maths is real.

    Embeddings, attention, masking, softmax, layer normalisation and sampling all work the way they do in GPT-style models. They are just small enough here that every number fits on screen, and you can click any of them to see how it was worked out.

    02

    The knowledge is counted, not trained.

    A real model learns by adjusting billions of weights. This one has random weights, so its knowledge comes from counting which word followed which phrase in its reading. Turn “Training-text strength” down to zero in the settings and you will see the network on its own: it babbles.

    03

    So it is not ChatGPT.

    It repeats what it has read and falls apart outside it. Ask it for the capital of France and it knows; ask it why, and it does not. That is the point: it is small enough to watch, one step at a time.