JSON → Zod schemas

Client

Paste JSON to emit z.object schemas and matching z.infer types—handy for validating parsed data with Zod before you wire routers or server handlers.

Learn more: JSON and Zod

Emit Zod object schemas from a JSON sample so you can validate parsed values at runtime and derive TypeScript types with z.infer—useful next to fetch handlers and config loaders.

Schemas vs interfaces

Zod describes both the shape and runtime checks: strings, numbers, nested objects, and arrays can be composed and then narrowed with parse or safeParse. This generator outputs `z.object` trees from one example; you still decide which fields are optional, nullable, or part of a union.

One sample, many payloads

Arrays use the first element only to guess item shape; empty arrays become `z.array(z.unknown())`. Merge multiple real responses or refer to JSON Schema when you need a stricter contract than a single snapshot.

Related tools

For compile-time-only types without validators, use JSON → TypeScript interfaces on this hub. For published API contracts, consider JSON Schema validate and OpenAPI helpers when they match your workflow.

JSON → Zod

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Parses JSON in your browser and emits classes inferred from the sample shape. Nested objects become nested types; arrays use the first element only to guess item shape. Nothing is uploaded.

Schemas mirror one sample—use .optional(), z.union(), or .refine() when the API allows missing keys, multiple shapes, or stricter rules. Pair with z.infer for TypeScript types.

Common use cases

  • Draft `z.object` trees for `fetch` or webhook payloads before you add optionality and unions.
  • Turn example config JSON into parse-time validators next to your TypeScript types.
  • Share a starting schema in docs or PRs when the payload shape is stable enough to sample.

Common mistakes to avoid

  • Treating one response as the full contract

    Optional keys and alternate shapes only appear when your sample includes them—merge examples or use JSON Schema when you need a published contract.

  • Skipping review of numeric and null handling

    Integers vs floats and nullability are inferred from one example; tighten with z.int(), z.union([z.null(), z.string()]), or branded types as needed.

FAQ

Is Zod code generated on your servers?

No. Parsing and codegen run locally from the JSON you paste.

Should this replace hand-written schemas for production APIs?

Use it to bootstrap. For strict contracts, align with your OpenAPI or JSON Schema source and add tests that cover edge cases.

More tools

Related utilities you can open in another tab—mostly client-side.