JSON Schema Generator: Create Type Models from JSON
Generate JSON Schema or typed models (TypeScript, Python, Go, Rust, Java) from sample JSON instantly. No install required.
Try the free online tool mentioned in this guide:JSON Schema Generator
What is JSON Schema?
JSON Schema is a declarative language for validating and documenting JSON. It defines:
- Which fields are required.
- Expected data types (string, number, object, array).
- Constraints (min/max, pattern matching, enum values).
- Nested object structures.
You can use JSON Schema to validate API responses, generate type definitions, and auto-generate documentation.
From JSON sample to typed models
If you have a sample API response, you can infer a schema and generate type definitions. MyDevTools scans your JSON and produces:
- JSON Schema (Draft 2020-12) — for API documentation and validation.
- TypeScript types — export interfaces for type safety.
- Python models — Pydantic dataclasses.
- Go structs — Unmarshal into typed structs.
- Rust types — serde-compatible.
- Java / C# / Dart / Swift — language-specific types.
Example: API response to TypeScript
Sample JSON response:
`json
{
"id": 123,
"name": "Alice",
"email": "alice@example.com",
"posts": [
{"title": "First Post", "published": true}
]
}
`
Generated TypeScript:
`typescript
interface User {
id: number;
name: string;
email: string;
posts: Post[];
}
interface Post {
title: string;
published: boolean;
}
`
When to use schema generation
- API integration — model responses from third-party APIs.
- Backend validation — validate incoming JSON with schema rules.
- Frontend type safety — strong types in TypeScript/Python.
- Documentation — auto-generate API schema docs.
- Testing — generate mock data matching the schema.
Frequently asked questions
Can I generate models from incomplete JSON samples?
Yes, but inferred types may be loose. Add more examples to refine. Optional fields are inferred if some samples lack them.
Does this support OpenAPI / Swagger?
Current version generates JSON Schema and language-specific types. OpenAPI spec generation may be added later.
Can I customize the generated code?
Yes, export and edit. The generator is a starting point; refine constraints and field names in your IDE.