What is Zod and why should I use it?

Zod is a TypeScript-first schema declaration and validation library. You define a schema once and Zod infers the TypeScript type automatically. It is widely used for validating API responses, form data, environment variables, and configuration objects. Zod schemas are composable, chainable, and produce human-readable error messages. With z.infer , you get a TypeScript type that always stays in sync with your runtime validation logic.

How does the tool handle null values?

When a JSON field value is null, the tool generates z.null() for that field and adds a comment reminding you to replace it with the actual type. Null in a JSON sample usually means the field can be null at runtime but its real type is unknown from the sample alone. If the Mark null fields optional option is enabled, .optional() is also appended, making the field both null and undefined-safe. After generation, update these fields to types like z.string().nullable() or z.number().nullable().

What is the z.infer type alias?

z.infer extracts the TypeScript type that the Zod schema describes. For example, if userSchema defines id as z.number() and name as z.string(), then type User = z.infer produces { id: number; name: string }. The major advantage is that your TypeScript type and runtime validation are always in sync — you only update the schema and the type updates automatically.

How are arrays of objects handled?

Arrays of objects are merged into a single z.object() schema wrapped with z.array(). All element objects are combined, and any field that does not appear in every element is marked .optional(). This produces a flexible schema that handles realistic API responses where some fields are conditionally present. For empty arrays, the tool generates z.array(z.unknown()) since there is no information about the element type.

Can I use this output directly in my project?

Yes, with one step: make sure Zod is installed (npm install zod). The generated code is valid TypeScript and can be pasted directly into .ts or .tsx files. You may want to refine null fields, add .min() or .max() constraints to numbers and strings, or add .email() and .url() validators to string fields where appropriate. The generated schema gives you the correct structure — add validation rules on top as needed.

Why does the tool not support JSON arrays as root input?

A JSON array at the root cannot be mapped to a single named z.object() schema. To convert an array, wrap it in an object first — for example { "items": [...] } — generate the schema, and then extract the element schema from z.array(z.object({...})). Alternatively, set the input to one element of the array to get the element schema directly.

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JSON to Zod Schema Generator

Generate Zod validation schema code from a JSON sample object. Infers z.string(), z.number(), z.boolean(), z.array(), z.object(), and z.null() types automatically. Handles nested objects, arrays of objects with optional field detection, and outputs copy-ready TypeScript with import and z.infer type alias.

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How to Use JSON to Zod Schema Generator

How to Use the JSON to Zod Schema Generator

Step 1: Paste Your JSON

Paste any valid JSON object into the input panel. The Zod schema is generated instantly in the output panel.

Example input:

{
  "id": 1,
  "name": "Alice",
  "active": true,
  "role": "admin"
}

Generated output:

import { z } from 'zod'

export const rootSchema = z.object({
  id: z.number(),
  name: z.string(),
  active: z.boolean(),
  role: z.string(),
})

export type Root = z.infer<typeof rootSchema>

Step 2: Set the Schema Name

Use the Schema name field to name your schema. Enter User, ApiResponse, or ContactForm. The tool automatically generates:

The const name: userSchema, apiResponseSchema
The type alias name: User, ApiResponse

Step 3: Configure Output Options

Add import — include import { z } from 'zod' at the top
export keyword — prefix const and type with export
z.infer type alias — append type Name = z.infer<typeof nameSchema>
null fields optional — add .optional() to fields whose value is null

Step 4: Nested Objects

Nested objects are inlined as z.object({...}) within the parent schema:

export const appConfigSchema = z.object({
  database: z.object({
    host: z.string(),
    port: z.number(),
    ssl: z.boolean(),
  }),
})

Step 5: Arrays of Objects

Arrays of objects are inferred as z.array(z.object({...})). All elements are merged — fields that appear in only some elements are marked .optional().

Step 6: Copy and Use

Click Copy Zod Schema and paste directly into your project. Install Zod with npm install zod if you haven't already.

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JSON to Zod Schema Generator

How to Use JSON to Zod Schema Generator

How to Use the JSON to Zod Schema Generator

Step 1: Paste Your JSON

Step 2: Set the Schema Name

Step 3: Configure Output Options

Step 4: Nested Objects

Step 5: Arrays of Objects

Step 6: Copy and Use

Frequently Asked Questions

What is Zod and why should I use it?

How does the tool handle null values?

What is the z.infer type alias?

How are arrays of objects handled?

Can I use this output directly in my project?

Why does the tool not support JSON arrays as root input?

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