JSON to Zod Schema
Generate Zod validation schemas from JSON
JSON Input
Zod Schema
How to use JSON to Zod Schema
- •Paste a sample JSON value into the input panel. This can be any valid JSON: an object, an array, a primitive, or a deeply nested structure.
- •Inspect the generated Zod schema in the output panel. The tool maps JSON types to their Zod equivalents:
z.string(),z.number(),z.boolean(),z.object(),z.array(), andz.null(). - •Refine the schema as needed. For example, you might want to add
.min(),.max(),.email(), or.url()refinements that cannot be inferred from data alone. - •Copy the schema into your project and use it with
schema.parse(data)orschema.safeParse(data).
What is Zod?
Zod is a TypeScript-first schema declaration and validation library. Unlike TypeScript interfaces, which disappear at runtime, Zod schemas validate data at runtime while also inferring static TypeScript types. You write the schema once and get both compile-time safety and runtime validation.
This dual purpose makes Zod indispensable at system boundaries — anywhere data enters your application from the outside world. API route handlers, form submissions, environment variables, third-party webhook payloads, and file uploads all benefit from runtime validation. If the data does not match the schema, parse() throws a detailed ZodError with a path to every failing field.
Zod integrates seamlessly with popular frameworks: React Hook Form via @hookform/resolvers/zod, tRPC for end-to-end type-safe APIs, Next.js Server Actions, and many more. The TypeScript type inferred by z.infer<typeof schema> stays perfectly in sync with the validation logic, eliminating an entire class of bugs where types and validation diverge.
Common use cases
- •API route validation: Parse incoming request bodies in Next.js API routes or Express handlers to reject malformed data before it reaches your business logic.
- •Form validation: Use with React Hook Form or Formik to validate user input on both client and server with the same schema.
- •Environment variable validation: Define a schema for
process.envand parse it at startup to fail fast if a required variable is missing. - •Webhook ingestion: Validate payloads from Stripe, GitHub, or other webhooks so your handler code can trust the data shape.
FAQ
Q: Can the tool infer .optional() fields?
A: From a single JSON sample, every field appears required. To get optional fields, you may need to manually add .optional() to fields that are sometimes absent.
Q: Does it handle null values?
A: Yes. A null value generates z.null(). You may want to change this to z.string().nullable() or similar depending on your actual schema requirements.
Q: How is this different from JSON Schema? A: JSON Schema is a specification for describing JSON data. Zod is a JavaScript/TypeScript library. Zod schemas are executable code that validate at runtime and infer TypeScript types. JSON Schema requires a separate validator library and a separate type generation step.
Is my data safe?
Yes. This tool runs entirely in your browser. Your data is never sent to our servers.
How to use JSON to Zod Schema
- Paste a sample JSON value into the input panel. This can be any valid JSON: an object, an array, a primitive, or a deeply nested structure.
- Inspect the generated Zod schema in the output panel. The tool maps JSON types to their Zod equivalents:
z.string(),z.number(),z.boolean(),z.object(),z.array(), andz.null(). - Refine the schema as needed. For example, you might want to add
.min(),.max(),.email(), or.url()refinements that cannot be inferred from data alone. - Copy the schema into your project and use it with
schema.parse(data)orschema.safeParse(data).
What is Zod?
Zod is a TypeScript-first schema declaration and validation library. Unlike TypeScript interfaces, which disappear at runtime, Zod schemas validate data at runtime while also inferring static TypeScript types. You write the schema once and get both compile-time safety and runtime validation.
This dual purpose makes Zod indispensable at system boundaries — anywhere data enters your application from the outside world. API route handlers, form submissions, environment variables, third-party webhook payloads, and file uploads all benefit from runtime validation. If the data does not match the schema, parse() throws a detailed ZodError with a path to every failing field.
Zod integrates seamlessly with popular frameworks: React Hook Form via @hookform/resolvers/zod, tRPC for end-to-end type-safe APIs, Next.js Server Actions, and many more. The TypeScript type inferred by z.infer<typeof schema> stays perfectly in sync with the validation logic, eliminating an entire class of bugs where types and validation diverge.
Common use cases
- API route validation: Parse incoming request bodies in Next.js API routes or Express handlers to reject malformed data before it reaches your business logic.
- Form validation: Use with React Hook Form or Formik to validate user input on both client and server with the same schema.
- Environment variable validation: Define a schema for
process.envand parse it at startup to fail fast if a required variable is missing. - Webhook ingestion: Validate payloads from Stripe, GitHub, or other webhooks so your handler code can trust the data shape.
FAQ
Q: Can the tool infer .optional() fields?
A: From a single JSON sample, every field appears required. To get optional fields, you may need to manually add .optional() to fields that are sometimes absent.
Q: Does it handle null values?
A: Yes. A null value generates z.null(). You may want to change this to z.string().nullable() or similar depending on your actual schema requirements.
Q: How is this different from JSON Schema? A: JSON Schema is a specification for describing JSON data. Zod is a JavaScript/TypeScript library. Zod schemas are executable code that validate at runtime and infer TypeScript types. JSON Schema requires a separate validator library and a separate type generation step.
Is my data safe?
Yes. This tool runs entirely in your browser. Your data is never sent to our servers.