JSON to Schema Generator

Free

Generate JSON Schema from any JSON document. Infer types, detect formats (email, URI, datetime, UUID), toggle required fields. Draft 2020-12 output for API contract testing and validation.

#json-schema#api-testing#contract-testing#validation

Schema Generator

JSON → JSON Schema (Draft 2020-12)

Required fieldsAllow additional properties

Detected formats:date-timeemailuri

JSON Input

Generated Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Generated Schema",
  "description": "Auto-generated from JSON input",
  "type": "object",
  "properties": {
    "id": {
      "type": "string"
    },
    "name": {
      "type": "string"
    },
    "email": {
      "type": "string",
      "format": "email"
    },
    "isActive": {
      "type": "boolean"
    },
    "age": {
      "type": "integer"
    },
    "lastLogin": {
      "type": "string",
      "format": "date-time"
    },
    "profileUrl": {
      "type": "string",
      "format": "uri"
    },
    "roles": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "address": {
      "type": "object",
      "properties": {
        "city": {
          "type": "string"
        },
        "zip": {
          "type": "string"
        },
        "country": {
          "type": "string"
        }
      },
      "required": [
        "city",
        "zip",
        "country"
      ],
      "additionalProperties": false
    }
  },
  "required": [
    "id",
    "name",
    "email",
    "isActive",
    "age",
    "lastLogin",
    "profileUrl",
    "roles",
    "address"
  ],
  "additionalProperties": false
}

Frequently Asked Questions(click to expand)

What is JSON Schema?

JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. It's widely used for API contract testing, form validation, and data pipeline verification.

What formats does this tool detect?

The generator automatically detects these string formats: date-time, date, time, email, URI, UUID, and IPv4. These are annotated with the JSON Schema "format" keyword for richer validation.

Which JSON Schema draft version is used?

This tool generates schemas compliant with JSON Schema Draft 2020-12, the latest standard.