Structured JSON at Scale: How Ollama's Constrained Decoding Transforms Local LLM Development

JSON parsing from local LLMs has been notoriously fragile—models often wrap outputs in markdown or add explanatory text, breaking downstream pipelines. Ollama 0.3.0 introduces constrained decoding through JSON schema support, which eliminates these failures at the inference level and delivers a 6.4x performance boost. This transforms local LLM deployments from brittle post-processing workarounds to production-grade structured output systems.