JSON Schema to Zod
Convert JSON Schema documents to Zod validators: map keywords, resolve $ref and $defs, and review unsupported keyword diagnostics.
Why convert JSON Schema to Zod
JSON Schema describes a contract that many languages can validate, while Zod validates data at runtime in TypeScript and infers static types. Converting JSON Schema to Zod gives a TypeScript app a practical runtime guard when an external API, gateway, or schema registry owns the contract.
How keywords map to Zod
Objects become z.object with required keys kept and others marked .optional(). Strings with email, uri, and date-time formats map to the matching Zod string validators. Numbers, integers, booleans, and arrays map directly, and enum, const, oneOf, anyOf, and allOf map to Zod enums, literals, unions, and intersections.
Resolving $ref, $defs, and definitions
Shared subschemas under $defs (Draft 2019-12 and 2020-12) or definitions (Draft 7) are emitted as separate exported Zod schemas. A $ref like #/$defs/Address is rendered as a reference to the AddressSchema export, so the generated code stays readable and reusable.
const result = OrderSchema.safeParse(await response.json());
if (!result.success) {
throw new Error("Unexpected JSON Schema payload");
}
return result.data;Keywords that need manual review
Some JSON Schema keywords have no reliable Zod equivalent and are skipped with a diagnostic instead of producing misleading output. Add the missing rules by hand after conversion.
- patternProperties and additionalProperties schemas.
- if / then / else and dependentSchemas conditionals.
- Custom string formats and numeric multipleOf constraints.
FrameworkKit vs the npm json-schema-to-zod package
Use the browser converter for fast, private conversion, shareable examples, and visible diagnostics. Use the npm json-schema-to-zod package or a build script when conversion should run inside your repository, CI, or tests so the Zod schemas stay in sync with the source contract.
JSON Schema to Zod keyword map
| JSON Schema | Generated Zod | Review before shipping |
|---|---|---|
| type, properties, required | z.object with required vs .optional() fields. | Confirm required arrays match the contract. |
| enum / const | z.enum, z.union of literals, or z.literal. | Check non-string enum values became literal unions. |
| type: ["string", "null"] | z.string().nullable(). | Verify nullable semantics for each field. |
| $ref to $defs / definitions | A separate exported Zod schema reused by name. | Ensure every referenced name resolves. |
| oneOf / anyOf / allOf | z.union or z.intersection. | Review discriminators and overlapping members. |
Use FrameworkKit to generate the starter code, then review the output before shipping it in production.
Generate with JSON Schema to ZodJSON to Zod resources
JSON Schema to Zod converter
Convert a JSON Schema document into Zod validators and inferred TypeScript types in the browser.
JSON Schema to Zod examples
Review object, enum, nullable, $defs, and $ref conversion examples before using the converter.
Zod to JSON Schema vs JSON Schema to Zod
Choose the right direction when moving between Zod schemas and portable JSON Schema contracts.
OpenAPI to Zod converter
Use the OpenAPI-aware converter when the source is an OpenAPI or Swagger document instead of raw JSON Schema.
Zod to JSON Schema Converter
Use the opposite direction when TypeScript-owned Zod schemas need portable JSON Schema output.
FAQ
Can JSON Schema be converted to Zod automatically?
Yes for common keywords. Objects, arrays, enums, formats, nullable types, unions, and $ref to local definitions convert cleanly. Conditional and pattern-based keywords need manual review.
Which JSON Schema drafts are supported?
The converter handles common keywords across Draft 7, 2019-12, and 2020-12, including shared subschemas under definitions or $defs.
Is this the npm json-schema-to-zod package?
No. This is a browser-only online converter for reviewing and copying Zod output. Use the npm package when conversion belongs inside your project build or tests.
Does the converter run on a server?
No. Conversion runs entirely in your browser and the pasted JSON Schema is never uploaded.
Related tools
Zod to JSON Schema Converter
Use a free browser-only online converter to turn Zod 4 schemas into JSON Schema for Draft 2020-12, Draft 7, AJV, or OpenAPI-compatible output.
OpenAPI to Zod
Turn OpenAPI schemas into Zod validators and lightweight typed fetch clients.
JSON to Zod Converter
Convert JSON to Zod schemas with strict objects, optional field inference, and inferred TypeScript types.