JSON Schema Generator
Generate a JSON Schema (Draft-07) from any JSON object instantly. Paste your JSON on the left, get a schema on the right.
JSON Input
Generated Schema
Options
About JSON Schema Generator
What is JSON Schema?
JSON Schema is a declarative language for annotating and validating the structure, constraints, and data types of JSON documents. It provides a contract for what JSON data is required and how to interact with it.
- Type Validation: Enforce data types (string, number, boolean, array, object, null, integer)
- Structure Validation: Define required properties, nested objects, and array item schemas
- Constraint Validation: Set minimum/maximum values, string patterns, and enum restrictions
- API Documentation: Used in OpenAPI/Swagger specs to document request/response shapes
How This Tool Works
Type Inference
| JSON Value | Schema Type |
|---|---|
| "hello" | string |
| 42 | integer |
| 3.14 | number |
| true / false | boolean |
| null | null |
| [...] | array (items inferred from first element) |
| {...} | object (properties inferred recursively) |
Options Explained
- Mark all fields as required
Adds a "required" array to every object listing all its property keys. Useful for strict API contracts.
- additionalProperties: false
Prevents extra properties not defined in the schema. Ensures strict object shapes.
- Schema title
Sets the top-level "title" field in the generated schema for documentation.
Common Use Cases
API Development
Generate schemas from API response samples to document and validate endpoints in OpenAPI specs.
Configuration Validation
Create schemas from config files to validate settings before deployment and catch errors early.
Data Pipeline Contracts
Define data contracts between services to ensure consistent data shapes across microservices.