JSON → TypeBox schemas

Client

Paste JSON to emit Type.Object definitions with Static types—useful when you want validators that compile to JSON Schema and stay ergonomic in TypeScript.

Learn more: JSON and TypeBox

Emit TypeBox `Type.Object` definitions from a JSON sample so you can derive TypeScript types with `Static` and reuse the same tree as JSON Schema–compatible validation.

JSON Schema alignment

TypeBox schemas compile to JSON Schema. That helps when you share contracts with OpenAPI tools, documentation generators, or cross-language pipelines—still edit `$id`, `$ref`, and formats to match your org’s standards.

Compared to Zod or Valibot

All three can validate parsed JSON at runtime. Choose TypeBox when you want schema-first JSON Schema output and TypeScript inference from one library. This generator only reflects one example; widen with `Type.Union` or optional fields when your API allows variants.

JSON → TypeBox

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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.

TypeBox builds JSON-Schema-compatible validators—tighten with Type.Optional(), Type.Union(), or integer formats when you outgrow one sample. Types use Static from @sinclair/typebox.

Common use cases

  • Bootstrap Type.Object trees for HTTP handlers when you already validate with Value.Check or Ajv compiled from TypeBox.
  • Share a JSON Schema–aligned draft with backend teams before you add $id and $ref in a real spec repo.
  • Compare inferred TypeBox with JSON → Zod or Valibot when choosing a runtime validator for the same payload.

Common mistakes to avoid

  • Treating one sample as exhaustive

    Optional fields and unions appear only when your paste includes them—merge examples or promote JSON Schema as the contract of record.

  • Assuming integers from JSON numbers

    Type.Number() matches any JSON number; use Type.Integer() or branded formats when your API guarantees whole numbers.

FAQ

Is TypeBox code generated on your servers?

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

Can I turn this into OpenAPI or pure JSON Schema?

TypeBox schemas are JSON Schema compatible; export or compile them with your usual toolchain—this page only emits the TypeScript scaffold.

More tools

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