What is a JSON Schema used for in AI?

JSON Schemas define the expected structure of structured outputs from language models. OpenAI function calling, tool use in Claude, and Gemini function declarations all use JSON Schema to constrain model output to a specific shape.

Does this support nested objects?

Yes. When you set a property type to "object", a nested properties section appears, allowing you to add child properties with the same full set of options (name, type, required, description).

Is the generated schema compatible with OpenAI and Claude?

The output follows JSON Schema draft-07 which is the basis for both OpenAI function calling schemas and Anthropic tool use schemas. Minor provider-specific extensions (like "strict" mode) can be added manually after copying.

AI JSON Schema Builder

Visually build JSON schemas for AI function calling and structured output.

Properties

required

Generated Schema

{
  "type": "object",
  "properties": {}
}

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FAQ

What is a JSON Schema used for in AI?: JSON Schemas define the expected structure of structured outputs from language models. OpenAI function calling, tool use in Claude, and Gemini function declarations all use JSON Schema to constrain model output to a specific shape.
Does this support nested objects?: Yes. When you set a property type to "object", a nested properties section appears, allowing you to add child properties with the same full set of options (name, type, required, description).
Is the generated schema compatible with OpenAI and Claude?: The output follows JSON Schema draft-07 which is the basis for both OpenAI function calling schemas and Anthropic tool use schemas. Minor provider-specific extensions (like "strict" mode) can be added manually after copying.

Visual form-based JSON Schema builder designed for AI function calling and structured output. Add properties with name, type (string/number/boolean/array/object), required flag, and description. Object-type properties support nested child properties. Generates a valid JSON Schema draft-07 object with a formatted preview and one-click copy.