JSON and API Tools

JSON Schema Generator Online Free

Generate JSON Schema from JSON online. Paste sample JSON and create a schema for API validation, backend models, OpenAPI workflows and data contracts.

Input JSON

Generated JSON Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "id": {
      "type": "number"
    },
    "name": {
      "type": "string"
    },
    "active": {
      "type": "boolean"
    },
    "tags": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "owner": {
      "type": "object",
      "properties": {
        "name": {
          "type": "string"
        },
        "email": {
          "type": "string"
        }
      },
      "required": [
        "name",
        "email"
      ]
    }
  },
  "required": [
    "id",
    "name",
    "active",
    "tags",
    "owner"
  ]
}

Generate Schema from JSON

JSON Schema Generator helps developers convert sample JSON into a reusable schema. This is useful for validating API payloads, defining contracts between frontend and backend teams, documenting data shapes and preparing structured validation rules.

Nested JSON Schema Support

Generate schema for nested JSON objects and arrays. The tool detects common value types such as string, number, boolean, object, array and null to create a clean starter schema.

Popular Use Cases

✓ API request and response validation
✓ Generate schema from sample JSON
✓ Backend model documentation
✓ OpenAPI and developer documentation
✓ Data contract validation

Frequently Asked Questions

What is JSON Schema Generator?

JSON Schema Generator creates a JSON Schema definition from sample JSON data.

Can I generate schema from nested JSON?

Yes. Nested objects and arrays can be converted into JSON Schema structure.

Is JSON Schema Generator free?

Yes. FormatForge JSON Schema Generator is free to use.

Does this tool store my JSON?

No. JSON processing happens locally in your browser.

Can I download the generated schema?

Yes. You can copy or download the generated JSON Schema.