AI file formats

Formats for trained AI models and the files that travel with them. Model weights are large arrays of numbers called tensors; some formats hold only those, others also describe the network so another program can run it. Training saves checkpoints, which can carry the optimiser state as well. Adapters such as LoRA hold a small set of extra weights that change a base model without replacing it. Beside the weights sit small text files: the tokenizer, which turns text into the numbers a language model reads, and the config, which gives the model’s architecture and sizes.