JSON to Zod Schema
Turn a sample JSON object into a Zod schema with an inferred TypeScript type — 100% in your browser.
🔒 Runs in your browser — nothing is uploaded.
Generate a Zod schema from JSON
Paste a representative JSON object and get a matching z.object({…}) Zod schema, plus an inferred TypeScript type via z.infer. Great for quickly adding runtime validation to an API response or form payload without hand-writing the schema.
The inference walks your JSON: objects become nested z.objects, arrays merge every element into one type (a key that only some records carry comes out .optional(), mixed kinds become a union), and primitives map to z.string(), z.number(), z.boolean() and friends. It all runs in your browser — your JSON is never uploaded.
Frequently asked questions
Does it detect optional or nullable fields?
Paste an array of records and it does: every element is read, so a key that only some of them carry comes out .optional(). A single lone object gives it nothing to compare, so add .optional() / .nullable() where your data allows it — a null value is inferred as z.null().
Which Zod version does the output target?
Standard Zod builder syntax that works with Zod 3. Numbers are emitted as z.number().int() when the sample value is a whole number.
Is my JSON uploaded?
No. The schema is generated entirely in your browser and your data never leaves your device.