JSON Schema to JSON

JSON Schema is the standard for describing the shape of JSON data — types, constraints, formats, and required fields. While validators check existing JSON against a schema, this tool does the inverse: it generates fresh, valid sample JSON from a schema definition.

Why generate sample JSON from a schema?

Sample data is invaluable for API mocking, frontend prototyping, fixture creation in tests, and onboarding new team members to a data model. Instead of writing examples by hand, derive them directly from the contract.

How values are chosen

Our generator follows a priority order: explicit default → first examples entry → const → first enum → format-aware sample (email, date-time, uuid, uri) → type-based fallback (empty string, 0, true, null). This produces realistic, schema-valid output every time.

Refs, oneOf, and anyOf

The generator resolves $ref pointers to definitions/$defs, follows the first branch of oneOf and anyOf for predictability, and recurses through nested objects and arrays without depth limits.

Schema features supported

• Draft 4, 6, 7, 2019-09, and 2020-12
• default, examples, const, enum
• format: email, date, date-time, uuid, uri
• $ref to #/definitions and #/$defs
• oneOf / anyOf (first branch picked)
• Nested objects, arrays, and required fields

Use the generated JSON as API mock fixtures, Postman variables, frontend stub data, or test inputs — all derived directly from your single source of truth.