JSON to Zod Schema Generator Online
Generate a Zod schema from a JSON sample instantly in your browser. Your JSON stays on your device.
Your JSON is parsed and converted to a Zod schema entirely in your browser, so it stays on your device and nothing is uploaded to a server.
Need plain TypeScript interfaces instead? Try JSON to TypeScript.
About JSON to Zod
This json to zod converter turns a sample JSON object or array into a ready-to-use Zod schema in seconds. Paste a real API response and it infers each value: strings become z.string(), whole numbers become z.number().int(), decimals z.number(), booleans z.boolean(), and null z.null(). Arrays become z.array() with their element shapes unified, and nested objects turn into nested z.object({...}) calls so the schema mirrors your data exactly. It is built for TypeScript developers who want a quick zod schema generator instead of hand-writing validators, whether you are wiring up form validation, typing an endpoint, or generating zod from json while exploring an unfamiliar payload. Name the root schema and optionally export an inferred type. Everything runs locally in your browser, so the JSON you paste is processed on your device and nothing is uploaded to a server.
Features
- Generates a named Zod schema from any JSON object or array
- Infers z.string(), z.number(), z.boolean() and z.null() from your sample
- Detects whole numbers and emits z.number().int() for them
- Turns nested objects into nested z.object({...}) calls
- Wraps arrays in z.array() and unifies mixed elements into a z.union()
- Optionally exports an inferred type with z.infer<typeof Schema>
- Lets you rename the root schema and shows JSON parse errors inline
- Copy the schema or download it as a .ts file
How to use the JSON to Zod
- Paste your JSON object or array into the input box.
- Set the schema name, or leave it as Schema.
- Toggle the inferred type export on or off to match your needs.
- Review the generated Zod schema, then copy it or download it as a .ts file.
Example
Input
{ "id": 1, "name": "Ada", "tags": ["a", "b"] }
Output
export const Schema = z.object({
id: z.number().int(),
name: z.string(),
tags: z.array(z.string()),
});
A flat JSON object becomes a typed z.object schema.
Common errors & troubleshooting
- The output shows an Invalid JSON banner with a line and column. — The JSON has a syntax issue such as a trailing comma, single quotes, or an unquoted key. Fix it at the reported line and column, then the schema regenerates.
- A field came out as z.array(z.unknown()) instead of a real element type. — That array was empty in your sample, so no element type could be inferred. Include at least one element and the schema will infer z.array() of its shape.
- A whole number was typed as z.number().int() but you wanted plain z.number(). — Integers are detected as z.number().int() from the sample. Edit the generated line to z.number() if the field can hold decimals too.
- An object property came out as z.null(). — Every sample value for that key was null. Provide a sample with a real value, or wrap the field in .nullable() yourself once you know its concrete type.
Frequently asked questions
- What does the JSON to Zod generator do?
- It reads a sample JSON object or array and produces a matching Zod schema in TypeScript, inferring a z.string(), z.number(), z.boolean(), z.null(), z.array() or z.object() for each value so you can drop it straight into your codebase.
- Does it support Zod v4?
- Yes. The schema uses the core constructors z.string(), z.number(), z.boolean(), z.null(), z.array() and z.object(), which are identical in Zod v3 and v4, so the output works with either version once you import z from zod.
- How are optional or nullable fields handled?
- Fields that are null in the sample become z.null(). Because a single sample cannot tell which keys are optional, nothing is marked .optional() automatically — add .optional() or .nullable() yourself where a field may be missing or null.
- How does it tell integers from floats?
- Whole numbers in your sample become z.number().int() and numbers with a decimal part become z.number(). If a field can hold both, change the generated line to z.number() so it accepts either.
- How are nested objects and arrays converted?
- Nested objects become nested z.object({...}) calls so the schema mirrors your JSON, and arrays become z.array() with the element schema inside. An empty array becomes z.array(z.unknown()).
- Is my JSON sent anywhere when I generate the Zod schema?
- No. The JSON to Zod conversion runs entirely in your browser, so the data you paste is processed locally and never leaves your device.
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