LLM Structured Outputs Guide 2026: JSON Mode, Instructor & Outlines
Structured outputs are no longer optional for serious LLM production systems. A 2026 enterprise survey found that 74% of LLM production applications now use some form of structured output, up from roughly 40% two years ago. The shift is driven by a simple operational reality: free-form text extraction breaks pipelines, structured schema enforcement does not. This guide covers the full stack — from why naive prompting fails to native APIs, Instructor, Outlines, Pydantic patterns, and retry strategies that hold up in production. ...