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JSON Schema Validator / Generator

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Options

Status
Idle
Supported rules
type, required, properties, items
enum, minLength, minimum
additionalProperties: false
type: ["string", "null"]

What is a JSON Schema Validator / Generator?

A JSON Schema Validator / Generator helps you create JSON Schema from sample JSON and validate JSON data against an existing schema.

This is useful for API contracts, backend validation, testing structured responses, and documenting expected payload formats.

How to use the JSON Schema Validator / Generator

  1. Paste JSON into the input field.
  2. Click Generate schema to create a JSON Schema.
  3. Edit or replace the schema if needed.
  4. Click Validate JSON to validate the input against the schema.

Tips

  • Generated schemas are useful as a starting point, but you may want to refine them manually.
  • Validation errors help identify which field or path does not match the schema.
  • Required fields can be toggled when generating object schemas.
  • This tool is useful for APIs, tests, automation, and AI JSON output validation.
  • You can manually add enum, minLength, minimum, nullable types, and additionalProperties false.

Example JSON Schema

You can also edit the generated schema manually. This version supports common rules such as type, required, enum, minLength, minimum, nullable types, array items, and additionalProperties. 

{
  "type": "object",
  "required": ["name"],
  "properties": {
    "name": {
      "type": "string",
      "minLength": 2
    },
    "age": {
      "type": "integer",
      "minimum": 18
    },
    "status": {
      "type": "string",
      "enum": ["active", "disabled"]
    },
    "nickname": {
      "type": ["string", "null"]
    }
  },
  "additionalProperties": false
}

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JSON Schema Validator / Generator FAQ

Can this tool generate JSON Schema from JSON?
Yes. It can generate a starter schema structure from sample JSON.
Can it validate JSON against a schema?
Yes. It validates JSON using the provided schema and shows validation errors.
Which schema rules are supported?
This version supports common rules such as type, required, properties, items, enum, minLength, minimum, nullable type arrays, and additionalProperties false.
Is my JSON stored?
No. It is processed only in your browser.