JSON Schema Generator

What this does

Give it a sample JSON, get back a Draft-07 schema. Seconds instead of writing it by hand.

When you need JSON Schema

• LLM structured output: OpenAI function calling, Anthropic Tool Use, Gemini function calling — they all want a schema so the model returns the right shape.
• Validate API responses: AJV, zod, joi all work with JSON Schema. Catch malformed data before it crashes your app.
• Generate TypeScript types: the json-schema-to-typescript package turns a schema into TS interfaces.
• API documentation: OpenAPI/Swagger uses JSON Schema to describe request and response shapes.

Tips for LLM use

• Enable "All fields required" — LLMs often skip optional fields when uncertain.
• Enable "additionalProperties: false" for strict mode — the model won't invent extra fields.
• Disable "Add examples" if the schema is for production validation (examples are unnecessary metadata).