JSON to JSON Schema generator

How to use it

1. Enter json input and root type name.
2. The result appears straight away and updates as you edit.
3. Copy the result, or copy a link that keeps the same values to share it.

How it is calculated

integer for whole numbers, number for decimals, string and boolean, array with items, and object with properties. Keys present in every array item go into required, null adds "null" to type, and mixed values become {} (any value).

Example

Inputs: Root type name = Root. Result: Generated code: { "$schema": "https://json-schema.org/draft/2020-12/schema", "title": "Root", "type": "object", "properties": { "id": { "type": "integer" }, "name": { "type": "string" }, "email": { "type": "string" }, "is_active": { "type": "boolean" }, "balance": { "type": "number" }, "tags": { "type": "array", "items": { "type": "string" } }, "address": { "type": "object", "properties": { "city": { "type": "string" }, "postal_code": { "type": "string" } }, "required": [ "city", "postal_code" ] }, "orders": { "type": "array", "items": { "type": "object", "properties": { "order_id": { "type": "string" }, "total": { "type": "number" }, "coupon": { "type": [ "string", "null" ] } }, "required": [ "order_id", "total", "coupon" ] } } }, "required": [ "id", "name", "email", "is_active", "balance", "tags", "address", "orders" ] }; Types generated: 3; Fields: 13.

{
  "id": 1024,
  "name": "Sara Ahmed",
  "email": "sara@example.com",
  "is_active": true,
  "balance": 1520.75,
  "tags": ["vip", "riyadh"],
  "address": { "city": "Riyadh", "postal_code": "12211" },
  "orders": [
    { "order_id": "A-1", "total": 99.5, "coupon": "EID10" },
    { "order_id": "A-2", "total": 120, "coupon": null }
  ]
}

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Root",
  "type": "object",
  "properties": {
    "id": {
      "type": "integer"
    },
    "name": {
      "type": "string"
    },
    "email": {
      "type": "string"
    },
    "is_active": {
      "type": "boolean"
    },
    "balance": {
      "type": "number"
    },
    "tags": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "address": {
      "type": "object",
      "properties": {
        "city": {
          "type": "string"
        },
        "postal_code": {
          "type": "string"
        }
      },
      "required": [
        "city",
        "postal_code"
      ]
    },
    "orders": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "order_id": {
            "type": "string"
          },
          "total": {
            "type": "number"
          },
          "coupon": {
            "type": [
              "string",
              "null"
            ]
          }
        },
        "required": [
          "order_id",
          "total",
          "coupon"
        ]
      }
    }
  },
  "required": [
    "id",
    "name",
    "email",
    "is_active",
    "balance",
    "tags",
    "address",
    "orders"
  ]
}

Limits and caveats

• It adds no constraints such as minLength, format or enum, so add them by hand.
• Nested objects are written inline, without $defs.