JSON to TypeScript Converter
Generate clean TypeScript interfaces and type definitions from JSON online. Automatically infers nested types, optional fields, and arrays.
How JSON → TypeScript Works
- Recursively walks JSON trees to identify primitive types (string, number, boolean, null).
- Creates modular, exported TypeScript interfaces for nested objects.
- Infers array item types (e.g. string[], User[], (string | number)[]).
Example Input & Output
Analyzes data types and nested structures in the JSON payload, generating strongly-typed TypeScript interfaces with child object references.
{
"id": 101,
"name": "Sandeep",
"active": true,
"scores": [95, 88, 92],
"profile": {
"title": "Senior Engineer",
"github": "sandeep"
}
}export interface RootObject {
id: number;
name: string;
active: boolean;
scores: number[];
profile: Profile;
}
export interface Profile {
title: string;
github: string;
}Common Use Cases
Frontend API Typing
Quickly generate types for Axios, Fetch, or React Query API response payloads.
Backend Contract Definition
Scaffold TypeScript types from raw JSON database models.
Key Specifications & Gotchas
Null Values
Fields with null values are typed as any or null unless concrete values exist in other array records.
Frequently Asked Questions
How do I generate TypeScript interfaces from JSON?
Paste any sample JSON object into the input editor, and complete TypeScript interface declarations will be generated in real time.
Does it support nested objects and arrays?
Yes, nested structures are extracted into separate, cleanly named interfaces.
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