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JSON Schema Generator

Generate a JSON Schema (Draft-07) from a sample. Use it for LLM structured output (OpenAI, Anthropic, Gemini), API response validation, or TypeScript type generation. Runs 100% in your browser.

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Sample JSON

Options

All fields required Add title from key Add examples from values additionalProperties: false (strict)

JSON Schema (Draft-07)

Keys

Required

Max depth

Generate a JSON Schema from a sample. Use the result for LLM structured output (OpenAI, Anthropic, Gemini), API validation, or TypeScript type generation.

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).