Output Formatting

Also known as: structured output, response format

Output formatting instructs the model to produce its response in a specific structure — such as JSON, Markdown, a numbered list, or a table — rather than free-form prose. Explicit format instructions in the system or user prompt, combined with structured output API features where available, allow downstream code to parse the response reliably. Poor or ambiguous format instructions are a leading cause of integration failures in LLM-powered pipelines.