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JSON Schema Generator

Draft-07FreePrivate

Generate a valid JSON Schema (draft-07) from any JSON object. Infers types, marks required fields, and handles nested structures.

JSON Input
Generated Schema
Ctrl+Enter Generate

JSON Schema Generator Online

Generate a valid JSON Schema (draft-07) from any JSON object instantly. Infers types, marks required fields, handles nested objects and arrays. no configuration needed. Ready to drop into ajv, Postman, or any JSON Schema validator.

Why Use JSON Schema?

Data Validation
Catch missing fields, wrong types, and extras before production. Paste samples into the JSON Formatter, then iterate with the combined schema workflow page.
API Contracts
Document request/response shapes beside OpenAPI. Generate client types using JSON → TypeScript once the schema matches reality.
Data Consistency
Keep microservices aligned on the same structure. When two services disagree, diff exported fixtures with JSON Diff and flatten nested events via JSON Flatten before schema inference.

How to Use

  1. Paste your JSON into the left panel
  2. Set an optional schema title in the toolbar
  3. Click Generate Schema or press Ctrl+Enter
  4. Copy or download as .json

Example

Input JSON
{
  "name": "Alice",
  "age": 30,
  "active": true
}
Schema (draft-07)
{
  "$schema": "…/draft-07/schema#",
  "type": "object",
  "properties": {
    "name":   { "type": "string"  },
    "age":    { "type": "integer" },
    "active": { "type": "boolean" }
  },
  "required": ["name","age","active"]
}

Features

  • JSON Schema draft-07 output
  • Infers string, integer, number, boolean, null
  • Detects nested objects and arrays recursively
  • Marks non-null fields as required
  • Heterogeneous arrays get anyOf schemas
  • Download schema as .json file

Frequently Asked Questions

What is JSON Schema used for?

JSON Schema is used to validate the structure and types of JSON data. Common uses: API request/response validation, form validation, database schema enforcement, and auto-generating documentation.

Which JSON Schema version does this generate?

It generates JSON Schema draft-07, which is widely supported by validators like ajv, Postman, and most modern tooling.

Can I use the schema with ajv?

Yes. The generated schema is fully compatible with ajv. Just pass the schema to ajv.compile(schema) and use the returned validator function.

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