Tools / JSON Schema → TypeScript / Zod

JSON Schema → TypeScript & Zod

Paste a JSON Schema from an API spec or config contract and get a TypeScript interface plus a Zod schema you can copy into your project. Everything runs in the browser — nothing is uploaded.

JSON Schema

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "UserProfile",
  "type": "object",
  "required": ["id", "email", "roles"],
  "properties": {
    "id": {
      "type": "string",
      "format": "uuid",
      "description": "Stable user id"
    },
    "email": {
      "type": "string",
      "format": "email"
    },
    "displayName": {
      "type": "string",
      "minLength": 1,
      "maxLength": 80
    },
    "age": {
      "type": "integer",
      "minimum": 0,
      "maximum": 150
    },
    "status": {
      "type": "string",
      "enum": ["active", "invited", "disabled"]
    },
    "roles": {
      "type": "array",
      "minItems": 1,
      "items": {
        "type": "string",
        "enum": ["admin", "editor", "viewer"]
      }
    },
    "address": {
      "title": "Address",
      "type": "object",
      "required": ["city"],
      "properties": {
        "city": { "type": "string" },
        "country": { "type": "string", "nullable": true },
        "tags": {
          "type": "array",
          "items": { "type": "string" }
        }
      },
      "additionalProperties": false
    },
    "metadata": {
      "type": "object",
      "additionalProperties": { "type": "string" }
    },
    "nickname": {
      "type": ["string", "null"]
    },
    "audit": {
      "$ref": "#/definitions/Audit"
    }
  },
  "additionalProperties": false,
  "definitions": {
    "Audit": {
      "type": "object",
      "required": ["at"],
      "properties": {
        "at": { "type": "string", "format": "date-time" },
        "by": { "type": "string" }
      }
    }
  }
}

// Numeric/string/array bounds (minLength, minimum, …) are enforced in Zod only.

export interface Audit {
  at: string;
  by?: string;
}
export interface Address {
  city: string;
  country?: string | null;
  tags?: string[];
}
export interface Root {
  /** Stable user id */
  id: string;
  email: string;
  displayName?: string;
  age?: number;
  status?: "active" | "invited" | "disabled";
  roles: "admin" | "editor" | "viewer"[];
  address?: Address;
  metadata?: {
  [key: string]: string;
};
  nickname?: string | null;
  audit?: Audit;
}

From contract to typed validators

JSON Schema is the lingua franca of API contracts, form builders, and config files. TypeScript describes the shape in your editor; Zod validates it at runtime. This free converter walks a schema once and emits both, so optional fields, enums, nested objects, arrays, and internal $refs stay consistent across outputs.

How schema keywords map to Zod

JSON Schema	Zod output
`type: object` + `properties`	`z.object({...})`; optional keys use `.optional()`
`type: integer`	`z.number().int()`
`enum: ["a","b"]`	`z.enum(["a","b"])`
`type: ["string","null"]` / `nullable`	`.nullable()`
`format: email\|uuid\|uri\|date-time`	`.email()`, `.uuid()`, `.url()`, `.datetime()`
`additionalProperties: false`	`.strict()`
Circular `$ref`	`z.lazy(() => …)`
`minLength` / `minimum` / `minItems`	Zod `.min()` / `.max()` chains (TS ignores bounds)

Need to reshape JSON or YAML payloads instead of schemas? Use the JSON ⇄ YAML ⇄ TypeScript converter.

FAQ

Which JSON Schema drafts are supported?

The converter targets the common draft-07 subset and tolerates 2020-12 documents. Supported highlights include objects, arrays/tuples, enums, const, oneOf/anyOf/allOf, nullable, formats, constraints, descriptions, and internal $refs. External $refs, if/then/else, patternProperties, and not are ignored with a notice.

Is my schema uploaded anywhere?

No. Parsing and codegen run entirely in your browser. The last input and options are kept in localStorage on your device only so a refresh does not wipe your work.

Which Zod version is the output for?

Generated schemas use Zod 4-style APIs (z.object, .optional, .nullable, .strict, z.lazy, z.infer, and format helpers like .email() / .uuid()). Adjust imports if your project pins an older major.

What about OpenAPI schemas?

OpenAPI component schemas that look like JSON Schema objects often work, including nullable: true. Full OpenAPI documents are not expanded — paste the schema object (or $defs / components.schemas entry) you care about.