TypeScript to JSON Schema

What Can TypeScript to JSON Schema Do?

The TypeScript to JSON Schema tool is a pure frontend online tool for converting TypeScript type definitions into JSON Schema. It supports interface, type aliases, enum, primitive types, arrays, nested objects, union types, optional properties, and literal types. The generated JSON Schema can be used for API documentation, form validation, code generation, and more. All conversion is done locally in your browser — data is never uploaded to any server.

Core Features

• Interface Conversion: Converts TypeScript interface to JSON Schema object type, automatically extracting required fields
• Type Aliases: Supports type definition conversion including union types, intersection types, and literal types
• Enum Support: Converts TypeScript enum to JSON Schema enum array
• Union Types: Literal unions become enum, type unions become oneOf
• Nested Objects: Recursively converts nested interface and type references

How to Use

Step 1: Select JSON Schema version (Draft 2020-12 or Draft 7).

Step 2: Enter TypeScript type definitions in the text area, or click "Load Example".

Step 3: Click "Convert Schema" or use Ctrl+Enter to view the generated JSON Schema.

Step 4: Click "Copy Schema" to copy to clipboard, or "Download JSON" to save as a file.

Use Cases

API Documentation

Convert TypeScript interface definitions to JSON Schema for OpenAPI/Swagger documentation generation, ensuring frontend-backend type consistency.

Form Validation

Use JSON Schema to drive frontend form validation (e.g., ajv, jsonschema libraries), auto-generating validation rules from TypeScript types.

Code Generation

Generate JSON Schema from TypeScript types, then use it to generate type definitions in other languages, mock data, or documentation.

Config Validation

Convert config file TypeScript types to JSON Schema for validating JSON/YAML configuration files.

Extended Knowledge

JSON Schema is a standard for describing JSON data structures, with the latest version being Draft 2020-12. TypeScript's type system has a natural correspondence with JSON Schema: string maps to {"type":"string"}, number maps to {"type":"number"}, interface maps to {"type":"object","properties":{...}}. Optional properties prop?: type are excluded from the required array. Union type 'a'|'b' becomes {"enum":["a","b"]}, string|number becomes {"oneOf":[{"type":"string"},{"type":"number"}]}. Array Type[] becomes {"type":"array","items":{...}}.

FAQ