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Evaluation and testing

Structured Output Tester

Test whether your LLM correctly generates structured JSON, XML, or TypeScript objects matching your defined schema. Supports function calling, JSON mode, and constrained generation testing across GPT-4o, Claude 3.5, and Gemini 2.0 Flash.

Run Structured Output Tester Interactively 100% client-side execution in your browser. Zero data retention.
Open Interactive Tool

What Problem Structured Output Tester Solves

Production AI deployments require predictable token economics, rigorous parameter verification, and deterministic schema handling. Structured Output Tester isolates parameters client-side before payloads hit third-party foundation model APIs.

Primary Production Use Cases

  • Validate function calling output schemas
  • Test JSON mode reliability across models

Security & Data Privacy Considerations

All computations execute locally in browser memory. No prompt payloads, test inputs, or secret credentials are ever retained or stored on central servers.

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