JSON Schema Generator
Generate JSON Schema (Draft 7) from any JSON object or array with recursive type detection and required fields.
JSON Schema Generator
Generate a JSON Schema (Draft 7) from any JSON object or array
Options
Paste JSON above and click "Generate" to create a JSON Schema
What is a JSON Schema Generator?
A JSON Schema generator is a tool that takes a sample JSON object or array and automatically creates a JSON Schema definition that describes its structure. JSON Schema is a declarative language for validating the format, types, and constraints of JSON data: widely used in API documentation (OpenAPI/Swagger), form validation, and data pipeline contracts.
CodeHelper's JSON Schema Generator produces Draft 7 schemas with recursive type detection for nested objects, arrays with merged item types, integer vs number distinction, and optional required fields and description placeholders.
Key Features
- Draft 7 Output: Generates schemas compliant with the JSON Schema Draft 7 specification.
- Type Detection: Identifies string, number, integer, boolean, null, object, and array types automatically.
- Nested Objects: Recursively builds schema definitions for deeply nested structures.
- Array Merging: Analyzes all items in an array to build a unified items schema.
- Required Fields: Toggle to mark all present properties as required.
How to use the JSON Schema Generator
- Paste a sample JSON object or array into the input.
- Optionally set a schema title and toggle required/description options.
- Click Generate to produce the JSON Schema.
- Copy or download the schema for use in your project.
Whether you are documenting REST APIs, building form validators, or setting up data contracts between services, this free JSON Schema generator saves you from writing schemas by hand.
To test data against the generated schema, use the validation tab of the JSON Formatter. If you need runtime validation in code instead, JSON to Zod generates Zod schemas, Go structs, and Pydantic models from the same sample JSON.
Validating payloads from a third party service? The data validation APIs in the directory cover addresses, emails and VAT numbers with their free tiers.
Frequently Asked Questions
How do I generate a JSON Schema from a JSON object?
Paste a sample JSON object or array into the generator and it infers the schema automatically: property types, nested objects, array item types, and optionally a required list. You then refine constraints like minLength or enum by hand where needed.
What is JSON Schema used for?
JSON Schema validates the structure and types of JSON data. Typical uses: validating API request and response bodies, documenting APIs via OpenAPI/Swagger, form validation, editor autocomplete for config files, and data contracts between services.
Which JSON Schema draft should I use?
Draft 7 remains the most widely supported version across validators (Ajv, python-jsonschema, editors) and is what this tool generates. Draft 2020-12 is the current specification and is required by OpenAPI 3.1, but tooling support is still uneven.
Can a generated schema be used with OpenAPI or Swagger?
Yes. OpenAPI 3.x schemas are JSON Schema based, so a generated Draft 7 schema drops into a components/schemas section with little or no modification. OpenAPI 3.0 uses a slightly restricted dialect, OpenAPI 3.1 accepts full JSON Schema.
Related
Free forever, no ads, no tracking. Support the project