JSON Schema Sample Data Generator
Generate realistic sample JSON from a JSON Schema. Great for creating mock data, test fixtures, and LLM structured-output examples.
Input JSON Schema
Supported keywords
- Types:
string,number,integer,boolean,null,array,object(including type arrays) - Strings:
format(email, date-time, date, time, uri, uuid, hostname, ipv4, ipv6, password),pattern,minLength/maxLength,enum,const - Numbers:
minimum/maximum,multipleOf,exclusiveMinimum/exclusiveMaximum - Objects & arrays:
properties,required,additionalProperties,items,minItems/maxItems - Composition:
oneOf/anyOf(first branch),allOf(merged),example/defaultvalues
About JSON Schema Sample Data Generator
Writing mock data by hand is tedious and drifts from your schema. This tool reads a JSON Schema and produces a sample document that satisfies it — respecting types, formats, required fields, and value constraints — so you get test fixtures and placeholder data that match your contract. With LLM structured output, a schema-compliant example is also a quick way to see what a model is expected to return.
Use it when you need fixtures for unit tests, placeholder payloads for frontend development, or a concrete example to pair with a published schema. Generated values are deterministic per schema, but they are meant as plausible examples, not production data. Recursive schemas are depth-limited to keep output finite, and the implementation covers the common draft-07 keyword set listed above.