🔒 Structured Output Playground

Lock any LLM's output to a JSON schema. A local model (Qwen2.5-3B) extracts structured data from free text. With constraints ON, the decoder can only emit tokens that keep the output conformant to your schema — right keys, right types, valid enums, every time.

Flip OFF and the same model free-styles: it may wrap the JSON in a markdown fence, or — more subtly — return valid JSON that violates your schema (a string where you asked for an integer, a value outside your enum). A good model complies often; constrained decoding makes it always.

Runs on ZeroGPU (H200) · no external API, no secrets · built by Ferr0 · pixelium.win · GitHub