What this does

Generates a Zod schema from a JSON sample, plus az.infer type for each schema. Use it to validate API responses or request bodies at runtime and get the matching static type for free. Nested objects become separate schemas that are declared before they are used.

Example

Input

{
  "id": 42,
  "name": "Ada",
  "verified": true,
  "tags": [
    "admin",
    "dev"
  ],
  "orders": [
    {
      "sku": "A1",
      "qty": 2
    },
    {
      "sku": "B2",
      "qty": 1,
      "note": "gift"
    }
  ]
}

Output with default options

import * as z from "zod";

export const OrderSchema = z.object({
    "sku": z.string(),
    "qty": z.number(),
    "note": z.string().optional(),
});
export type Order = z.infer<typeof OrderSchema>;

export const RootSchema = z.object({
    "id": z.number(),
    "name": z.string(),
    "verified": z.boolean(),
    "tags": z.array(z.string()),
    "orders": z.array(OrderSchema),
});
export type Root = z.infer<typeof RootSchema>;

How values are mapped

Strings, numbers, and booleans become z.string(), z.number(), and z.boolean().
Arrays become z.array(...); arrays with mixed element types become z.union([...]).
A field missing from some objects in an array gets .optional(); a field that is sometimes null becomes z.union([z.null(), ...]).
ISO 8601 timestamps become z.coerce.date() when date detection is on. Turn Detect dates and UUIDs off to keep z.string().

Things to know

The schema is inferred from your sample, so it describes exactly what you pasted. Integers and floats are both z.number(); add .int() yourself where it matters. The output imports from "zod" in the Zod 4 style (import * as z from "zod"). For plain compile-time types without runtime validation, useJSON to TypeScript.

Privacy

Generation runs in a Web Worker in your browser. The JSON is never uploaded.

JSON to Zod Schema Converter