Zod is a TypeScript-first schema declaration and validation library. It lets you define the shape and constraints of data, validate it at runtime, and automatically infer static TypeScript types from the schema. It is widely used in Next.js, tRPC, and React Hook Form projects.

What is z.infer and why is it included?

z.infer extracts the TypeScript type from a Zod schema. By including it in the output, you get both a runtime validator and a compile-time TypeScript type from a single source of truth, without writing a separate interface.

How are integer and float numbers handled differently?

If the JSON value is a whole number (no decimal), the tool generates z.number().int() which validates that the value is an integer at runtime. Decimal numbers generate z.number().

How are nested objects and arrays handled?

Nested objects generate their own named schema (e.g., AddressSchema) which is referenced in the parent. Arrays infer their element type — arrays of objects generate an item schema, while arrays of primitives use z.array(z.string()) etc.

Can I add optional fields to the generated schema?

The generated schema marks all fields as required. To make a field optional, append .optional() to its type in the output — for example: email: z.string().optional(). You can also use .nullable() for fields that can be null, or .nullish() for fields that can be null or undefined.

Which version of Zod does the output target?

The generated code targets Zod v3, which is the most widely used version and is installed via `npm install zod`. The API is stable and the output should work with any Zod 3.x release.

Free · Browser-only · No sign-up

JSON to Zod Schema Generator

Convert any JSON object into a Zod v3 schema with z.infer type exports. Handles nested objects, arrays, integers, and all JSON primitives. Import the schema directly into your TypeScript project for runtime validation and type safety.

z.object / z.arrayz.infer typesNested schemasImport included100% offline

root name

json input

zod schema

About this tool

Generates a Zod v3 schema from any JSON object, including nested objects and arrays. The output includes a z.infer type export so you get both runtime validation and compile-time TypeScript types from one schema. Everything runs in your browser — no data is ever sent to a server.

Features

Nested schemas

Each nested object generates a named schema referenced by the parent

z.infer types

TypeScript type is exported alongside every schema automatically

Integer precision

Whole numbers generate z.number().int() for stricter validation

Array support

Arrays use z.array() with the correct inferred element type

Import included

The output starts with import { z } from "zod" — paste and go

Browser-only

No network requests — your JSON stays on your device

How to use

1
Paste JSON
Copy any JSON object or array into the input field.
2
Set root name
Rename the root schema from "Root" to something descriptive — it will be exported as RootSchema.
3
Generate
Click Generate Zod Schema. Nested objects create their own schemas, referenced in the parent.
4
Install Zod & import
Run npm install zod, then paste the generated code into your project and use the schema to validate data.

Frequently asked questions

Do I need to install anything to use this tool?

No. The generator runs in your browser. To use the generated schema in your project you need to install Zod: npm install zod (or yarn add zod / pnpm add zod).

Can I generate schemas for API responses?

Yes. Paste the JSON response from any API and the tool generates a schema you can use to validate future responses at runtime, catching breaking changes early.

How do I handle fields that could be multiple types?

The tool infers from a single sample. For union types (e.g., string | number), manually replace the inferred type with z.union([z.string(), z.number()]) in the output.

Is the output compatible with tRPC or React Hook Form?

Yes. The generated schemas are standard Zod v3 and work with tRPC input validators, React Hook Form resolver (@hookform/resolvers/zod), and any other Zod-compatible library.

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