Cómo usar: JSON to JSON Schema
- Paste a JSON example — an API response, a config file, a database record — or click Sample.
- For better results paste several examples as a JSON array: fields missing from some become optional, and different types become a union.
- Choose the draft, how required is decided, and whether to detect formats, build enums, forbid extra properties or keep examples.
- Copy or download the schema — or send it straight to the JSON Schema to TypeScript converter or the validator.
How the schema is inferred
- Types: strings, numbers, integers (whole numbers), booleans, null, objects and arrays. A field that is sometimes a number and sometimes null becomes
"type": ["number", "null"]. - Arrays: every item is merged into one
itemsschema, so an array of user objects gets one user schema with all keys seen. - Required: by default a key is required only if it appears in every object of that shape. With one example, all keys are required.
- Formats: strings that all look like an email, URI, UUID, date, date-time, time, IPv4 or IPv6 get a
format. - Enums: a string field with a few repeating values across many examples (like
status) becomes anenum.
An inferred schema describes your examples, not your intent — review it: tighten strings with minLength or pattern, add minimum/maximum to numbers and decide which fields are truly optional. Then check data against it with the JSON Schema Validator or generate types with JSON Schema to TypeScript.
También se busca como: json schema generator, generate json schema from json, infer json schema, json schema from example, create json schema online, json schema draft 2020-12, json to schema.
Herramientas que combinan con: JSON to JSON Schema
- JSON to TypeScript — Paste a JSON sample — an API response, a config — and get ready-to-use TypeScript interfaces with nested types, optional properties and union types.
- Formateador JSON — Pega el código JSON para formatearlo, minimizarlo o validarlo.
- OpenAPI / Swagger Validator — Paste an API specification to check it against the official OpenAPI schema, catch broken references and inconsistent path parameters, and see every endpoint at a glance.
- Generador de datos ficticios — Crea hasta 10 000 filas de datos de prueba realistas —usuarios, productos, pedidos, direcciones, empresas o registros API anidados— o diseña tu propio esquema.
Preguntas frecuentes
How do I generate a JSON Schema from JSON?
Paste the JSON here: the generator walks every value, writes the matching type, properties and items, marks keys as required and detects formats. Paste several examples in an array for a more accurate result.
Which JSON Schema draft should I use?
Draft 2020-12 is the current version and what OpenAPI 3.1 uses. Choose draft-07 for older tools and libraries that don’t support 2020-12 yet.
Why is a field not marked as required?
It was missing from at least one of your examples. Change “Required fields” to “Every key” if every field must always be present.
Can I turn the schema into TypeScript types?
Yes — click To TypeScript to open the schema in the JSON Schema to TypeScript converter.
¿Puedo instalar JSON to JSON Schema como aplicación web y utilizarla sin conexión?
Sí. JSON to JSON Schema es una aplicación web instalable (PWA): se instala desde el navegador, no se descarga desde una tienda de aplicaciones. Haz clic en «Instalar aplicación» en la parte superior de esta página en Chrome o Edge (Windows, macOS, Linux, ChromeOS) o, en Android, utiliza «Compartir» → «Añadir a la pantalla de inicio» en iPhone y iPad, o «Archivo» → «Añadir al Dock» en Safari 17+ en un Mac. A continuación, se abrirá en su propia ventana con su propio icono y, como se ejecuta íntegramente en tu navegador, seguirá funcionando sin conexión. Firefox en el ordenador de sobremesa no permite instalar aplicaciones web. Cómo funciona la instalación.