JSON to Zod Schema Generator
Convert JSON to Zod schemas online with nested objects, arrays, optional and nullable fields plus z.infer TypeScript types. Free, instant and private in your browser.
π Runs entirely in your browser β nothing is uploadedZod schemas generated from JSON
TypeScript types disappear at runtime, so data from an API, a form or localStorage is only as safe as the code that checks it. Zod closes that gap by validating values against a schema and inferring the TypeScript type from that same schema. This JSON to Zod converter writes the schema for you: paste a JSON sample and every object becomes a z.object, primitives map to z.string(), z.number() and z.boolean(), arrays become z.array(...), and nested objects get their own named schemas that are reused wherever they appear.
The tool is powered by quicktype, which merges every element of each array before inferring types. Fields that appear in only some items are marked optional, and values that are sometimes null are marked nullable, so the schema accepts the real data you saw rather than only its first element.
Schemas and inferred types together
By default the output also exports a TypeScript type for every schema using z.infer, giving you one source of truth for validation and static typing. Import the root schema and call RootSchema.parse(data) to validate an untrusted value and get a typed result, or safeParse when you want to handle errors without exceptions. Tick Schemas only if you prefer to declare types elsewhere. This is a natural companion to the JSON to TypeScript tool when you need runtime guarantees, not just compile-time hints.
Tips for stricter schemas
Generate from a representative sample with several array items and optional fields filled in. Then refine what a sample cannot show: add .email(), .url() or .uuid() to string fields, use z.enum for fields with a fixed set of values, constrain numbers with .int() or .min(), and decide whether unknown keys should be stripped or rejected with .strict(). All generation happens locally, so you can safely paste production payloads.
How to use
- Paste JSONPaste an API response or any JSON sample, or click Load sample.
- Name the rootSet the root schema name and decide whether to include inferred types.
- Copy the schemasCopy the TypeScript code or download a .ts file and validate with schema.parse().
Frequently asked questions
What does the output contain?
z.infer. Tick Schemas only to skip the type aliases.How are optional and nullable fields handled?
.optional() or .nullable(), so validation accepts the variations seen in real data.Which Zod version does it target?
z.object, z.array, z.string and z.number APIs that work in both Zod 3 and Zod 4.