Client-side converterJSON to TypeScriptJSON to GoJSON to DartToggle theme
CYF Types

JSON to Type Converter

Paste JSON and instantly generate TypeScript interfaces, TypeScript type aliases, Go structs, or Dart classes. Everything runs in your browser.

JSON Input

Format JSONClear inputPaste sample JSON
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Output Type

Generated Output

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export interface RootObjectProfile {
  email: string;
  verifiedAt?: null;
}

export interface RootObjectProjectsItemMetrics {
  stars: number;
  archived: boolean;
}

export interface RootObjectProjectsItem {
  id: string;
  title: string;
  metrics: RootObjectProjectsItemMetrics;
}

export interface RootObject {
  id: number;
  name: string;
  active: boolean;
  profile: RootObjectProfile;
  roles: string[];
  projects: RootObjectProjectsItem[];
}

How to convert JSON to Type models

A JSON to type converter turns sample API payloads into reusable models for strongly typed applications. Paste a valid JSON object or array into the input editor, choose a target language, and adjust the root model name to match your domain. The converter scans every property, detects strings, numbers, booleans, null values, nested objects, and arrays, then builds a structured model that is easier to maintain than handwritten boilerplate. When arrays contain multiple objects, their fields are merged so optional or nullable values are represented clearly in the generated output.

Supported target languages

This tool supports TypeScript Interface for application contracts, TypeScript Type for alias-based codebases, Go Struct for backend services and JSON tags, and Dart Class for Flutter or Dart data layers. TypeScript output uses nested declarations and nullable unions where appropriate. Go output maps JSON strings, numbers, booleans, arrays, and objects into idiomatic field definitions with serialized field tags. Dart output creates immutable classes with a constructor, a fromJson factory, and a toJson method so the generated model can move directly into client code.

Privacy Guarantee: All conversions happen locally in your browser

Your JSON is not uploaded to a server, sent to an external API, or stored by this converter. Formatting, validation, schema inference, and code generation run entirely in the browser session. That makes the tool suitable for quick local modeling of API responses, configuration files, mock data, and internal payloads. For sensitive production data, remove secrets before sharing output with teammates, but the conversion itself remains private on your device.