TTidy Utils
Developer

JSON Schema Generator From JSON

Paste example JSON, infer nested types and required fields, and control additional properties locally in your browser.

Generated schemas are starter drafts. Review formats, enums, ranges, nullable values, additional properties, and application rules before using them in production.

How to use JSON Schema Generator From JSON

Best for

  • Generating a first-pass JSON Schema from an example JSON object or array.
  • Documenting object properties, nested objects, array items, and inferred required fields.
  • Starting a validation schema or API contract before editing business rules by hand.
  • Comparing permissive schemas with stricter objects that block properties missing from the example.

Steps

  1. Paste representative JSON or load an object, array, or nested API sample.
  2. Choose whether object fields should be marked required.
  3. Choose whether objects should allow properties that were not present in the example.
  4. Review the generated schema for inferred types, arrays, nested objects, and required fields before copying it.

Notes

  • Generated schemas are drafts based on examples, not a complete validation contract.
  • Use this as a JSON schema builder for structure and type inference, then add formats, enums, ranges, and custom rules manually.
  • Blocking additional properties can make validation stricter, but only use it when the real contract rejects unknown fields.
  • Review nullable fields, enums, formats, minimums, maximums, and application-specific rules manually.

FAQ

Does JSON Schema Generator upload my JSON?

No. The schema is inferred locally in your browser from the JSON you paste.

Can this infer every validation rule?

No. It can infer structure and basic types from examples, but it cannot know domain-specific rules such as allowed values or numeric ranges.

Can I generate JSON Schema from an array of objects?

Yes. Paste a representative array and the generator will infer item properties, shared fields, nested objects, arrays, and basic value types.

What does additionalProperties mean in JSON Schema?

When additionalProperties is true, an object may contain fields not listed under properties. Set it to false only when the real data contract should reject unknown fields.