JSON Schema Generator
DeveloperGenerate JSON Schema from sample JSON data. Perfect for API documentation and validation.
What is This Tool?
A JSON Schema generator creates JSON Schema definitions from sample JSON data or from scratch using a visual editor. Define object structures, property types, validation constraints (required, min/max, patterns), and generate schemas for API validation, form generation, and documentation.
JSON Schema (draft-07/2020-12) is a vocabulary for annotating and validating JSON documents. Schemas define the expected structure, types, and constraints. They are used by API validators (Ajv, Joi), form generators (react-jsonschema-form), and API documentation (OpenAPI/Swagger).
Common Use Cases
API Validation
Generate schemas for validating REST API request/response bodies using Ajv, Joi, or Express validators.
OpenAPI Documentation
Create JSON Schema definitions for OpenAPI/Swagger component schemas that document your API contracts.
Form Generation
Generate schemas used by react-jsonschema-form, Angular JSON Schema Form, and other schema-driven form libraries.
Data Pipeline Validation
Define and enforce data contracts between services in event-driven architectures and ETL pipelines.
Frequently Asked Questions
Can I generate from sample JSON?
Yes. Paste sample JSON data and the tool infers types, required fields, and constraints to produce a starting schema you can refine.
Which JSON Schema version is used?
Draft-07 is most widely supported. Draft 2020-12 is the latest with additional features like $dynamicRef and prefixItems.
How do I validate data against a schema?
Use libraries like Ajv (JavaScript), jsonschema (Python), or built-in support in API frameworks. The schema defines the rules; the library enforces them.