JSON to Zod Schema Generator

Turn any JSON into a Zod schema plus its TypeScript type, ready to validate API responses and form data.

Generated code
Runs in your browser. Your JSON is never uploaded.

How to generate a Zod schema from JSON

  1. Paste a JSON object or array into the left box.
  2. Set the schema name. You get UserSchema plus a matching User type.
  3. Turn on Strict objects if unknown keys should fail validation.
  4. Copy the code or download it as a .schema.ts file.

Everything runs in your browser, so you can paste real API responses safely.

Why validate JSON with Zod?

TypeScript types disappear when your code runs. If an API changes or a user sends a bad request body, TypeScript can’t stop it. A Zod schema checks the data at runtime and gives you the TypeScript type from the same source, so the two never drift apart.

In an Express route, validate the request body before you touch the database:

const result = UserSchema.safeParse(req.body);
if (!result.success) {
  return res.status(400).json({ errors: result.error.flatten() });
}
const user = await User.create(result.data);

How JSON values map to Zod

JSON value Zod schema
Text z.string()
Email or URL text z.string().email() or z.string().url()
ISO date text z.coerce.date(), which turns the string into a Date
Whole number z.number().int()
Decimal number z.number()
Nested object A separate named schema
Field missing from some array items .optional()
null in some items .nullable()

Frequently asked questions

Does the output work with Zod 3 and Zod 4?

Yes. The generated methods work in both versions. Zod 4 also offers shorter forms such as z.email(), which you can switch to if you prefer.

How do I get the TypeScript type?

Each schema comes with a type line such as export type User = z.infer<typeof UserSchema>;, so you never write the interface by hand.

Why are dates converted with z.coerce.date()?

JSON has no date type, so dates arrive as strings. z.coerce.date() accepts the string and gives you a real Date object. If you want to keep strings, change it to z.string().

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