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JSON → TypeScript
JSON → TypeScriptReady
Indent
Sample JSON Payload
0 lines · 0 B
Raw input remains untouched until you click Format
Generated TypeScript InterfacesEditable
0 lines · 0 B
Ready to copy (⌘⇧C) or download (⌘S)

JSON to TypeScript Interface Generator

Generate clean TypeScript interfaces and type definitions from JSON payloads online. Automate frontend data typing with instant browser conversion.

Interface generation
Nested type extraction
Array item inference
Readonly & Optional options
Step-by-Step Guide

How to Use JSON → TypeScript Online

Follow these quick steps to process your data online directly in your browser with zero latency and 100% privacy.

1
Step 1Recursively walks JSON trees to identify primitive types (string, number, boolean, null).
2
Step 2Creates modular, exported TypeScript interfaces for nested objects.
3
Step 3Infers array item types (e.g. string[], User[], (string | number)[]).
Demonstration

Example Input & Output

Analyzes data types and nested structures in the JSON payload, generating strongly-typed TypeScript interfaces with child object references.

Sample JSON Payload
{
  "id": 101,
  "name": "Alex",
  "active": true,
  "scores": [95, 88, 92],
  "profile": {
    "title": "Senior Engineer",
    "github": "alex"
  }
}
Generated TypeScript Interfaces
export interface RootObject {
  id: number;
  name: string;
  active: boolean;
  scores: number[];
  profile: Profile;
}

export interface Profile {
  title: string;
  github: string;
}
Applications

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.

Guidelines

Specifications & Gotchas

Null Values

Fields with null values are typed as any or null unless concrete values exist in other array records.

Knowledge

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.

Workflow

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