JSON Schema Generator
Generate valid JSON Schema definitions automatically from sample JSON structures.
How to Use JSON Schema Generator
- Paste your JSON payload into the input box.
- Select your preferred JSON Schema specification draft.
- Click Generate JSON Schema to infer properties, types, and required fields.
- Copy your generated JSON Schema definition.
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Frequently Asked Questions
How does automated JSON Schema generation work from sample data?
The generator inspects the structure of your JSON object or array. It recursively infers primitive types (string, integer, number, boolean, null), maps nested object properties, generates required property lists, and defines item schemas for arrays.
Which JSON Schema drafts can be generated?
You can generate schemas compliant with JSON Schema Draft-07 (the standard format used by OpenAPI 3.0, AJV, and Swagger) or modern JSON Schema 2020-12 (which uses the updated URI and prefixItems specification).
How does the generator distinguish between integer and number types?
The engine uses Number.isInteger() on numerical values. Values without fractional decimals (such as 42 or 100) are assigned the strict 'integer' schema type, while floating-point numbers (such as 3.1415) are assigned 'number'.
How are arrays with multiple items analyzed?
When an array of objects is supplied, the generator inspects the elements to infer a uniform items schema containing the collective properties of the array items.
Can I use the generated schema to validate incoming API requests in backend apps?
Yes. The generated JSON Schema can be copied directly into backend validation libraries like ajv (Node.js), jsonschema (Python), or pydantic to enforce payload contracts on incoming API endpoints.