reasoning model

A reasoning model is a generative language or multimodal model designed and tuned to handle complex, multi-step reasoning tasks by allocating more inference resources or explicitly incorporating internal thinking phases before producing a final answer. In current practice, that reasoning is a tunable setting rather than a fixed property of a separate model class. The major vendors expose a reasoning effort or thinking level control on their general-purpose frontier models, and they meter the internal deliberation as reasoning tokens that count against the output budget.

These models represent a broader shift toward models that not only generate responses, but also plan, decompose, verify, and refine reasoning internally through long chain-of-thought traces or latent internal reasoning processes.