The process of continuing to train a pre-trained foundation model on a smaller, task-specific dataset to adjust its behavior or knowledge without retraining from scratch.
Technical implementation · AI Search Infrastructure
Fine-tuning is the process of continuing to train a pre-trained foundation model on a smaller, task-specific or domain-specific dataset to adjust its behavior, tone, or knowledge for a particular application. It modifies the model’s weights — updating its parametric knowledge — without retraining from scratch.
Fine-tuning is sometimes proposed as a fix for wrong or absent AI brand representations. In practice, it is not available to brands as a self-service action — the models that power ChatGPT, Perplexity, and Google AI Overviews are not fine-tunable by external parties. Fine-tuning is relevant in enterprise deployments where a company runs its own model instance, or when evaluating AI vendors who offer fine-tuned models as a product. For most brands, the parametric correction path runs through training data sources — Wikipedia, knowledge graphs, widely-cited publications — not fine-tuning.
Brands can fine-tune ChatGPT or Perplexity to correct how those platforms represent them. They cannot — these are closed production systems. Fine-tuning applies to models a brand controls directly.