JsonifyTools
    Schema Toolkit · 100% Local · Browser Only

    JSON Schema to TypeScript

    Turn JSON Schema into TypeScript interfaces for API clients, SDKs, frontend models, and documentation.

    Browser only Valid Schema / Data
    JSON Schema
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    TypeScript Interface
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    Schema Metrics

    Fields
    12
    Objects
    2
    Arrays
    1
    Constraints
    4

    Field Hierarchy Tree

    ❖Root(object)
    └─id*(integer)
    └─name*(string)
    └─email*(string)
    email
    └─active(boolean)
    └─createdAt(string)
    date-time
    └─profile(object)
    └─phone(string)
    └─country(string)
    └─company(string)
    └─roles(array)
    └─items[](string)

    Schema Constraints

    $.name(1 rule)
    minLength:1
    $.email(1 rule)
    format:email
    $.createdAt(1 rule)
    format:date-time
    $.roles[](1 rule)
    enum:["admin","developer","member"]
    TypeScript & Zod Type Generator
    Strict Type-Safe Engine

    Convert JSON Schema to TypeScript Interfaces & Zod Schemas

    Instantly turn JSON Schema specifications into strongly typed TypeScript interfaces, type aliases, Zod schemas, and TypeBox definitions. Ideal for building end-to-end type-safe API clients, SDK libraries, React Query hooks, NestJS DTOs, and Next.js Server Actions with 100% client-side privacy.

    TypeScript SupportTS 4.x / 5.x Ready
    Runtime ValidationZod & TypeBox Output
    OptionalitystrictNullChecks Compliant
    Privacy100% Client-Side

    Interactive TypeScript Code Generator Modes

    Select a target TypeScript generation format to inspect input schema and compiled code:

    TS Interface
    Source JSON Schema

    1. TypeScript Interface Export

    Generates clean, extensible TypeScript interfaces with optional fields (`?`), literal enum unions, and nullable types for frontend models.

    Input JSON Schema
    {
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "required": ["id", "username", "email"],
  "properties": {
    "id": { "type": "integer" },
    "username": { "type": "string" },
    "email": { "type": "string", "format": "email" },
    "role": { "type": "string", "enum": ["ADMIN", "MEMBER"] },
    "phoneNumber": { "type": ["string", "null"] }
  }
}
    Generated TypeScript / Zod Code
    export interface UserProfile {
  id: number;
  username: string;
  email: string;
  role?: 'ADMIN' | 'MEMBER';
  phoneNumber?: string | null;
}
    Type System Mapping

    JSON Schema to TypeScript Data Type Mapping Matrix

    Reference table mapping JSON Schema primitive types, arrays, enums, and references to TypeScript types:

    JSON Schema Type / KeywordCompiled TypeScript TypeSample Value
    type: "string"string"john_doe"
    type: "integer"number42
    type: "number"number99.99
    type: "boolean"booleantrue
    type: "null"nullnull
    type: ["string", "null"]string | null"text" | null
    type: "array", items: {...}Array<T> / T[]string[]
    type: "object", properties: {...}interface / Record<string, T>{ id: number }
    enum: ["A", "B"]'A' | 'B' / enum'A' | 'B'
    $ref: "#/$defs/Address"Addressnested interface

    Why, When, & How to Convert JSON Schema to TypeScript

    Why Generate TS Interfaces?

    Auto-generating TypeScript types from JSON Schema eliminates manual type duplication, prevents API runtime mismatch bugs, and ensures compile-time safety across frontend and backend applications.

    When to Use the Converter?

    Use when integrating third-party REST APIs, generating React Query data types, writing NestJS DTO classes, defining Next.js Server Action parameters, and publishing npm SDK packages.

    How Does the Generator Work?

    Paste your JSON Schema. The engine builds an Abstract Syntax Tree (AST), resolves `$ref` references, infers required vs optional keys, and formats valid TypeScript code in real time.

    Programmatic Build Pipeline Tooling (CLI & Node.js)

    Automate TypeScript type generation in your build scripts and CI/CD pipelines:

    npm install -g json-schema-to-typescript

# Convert a single JSON Schema file into TypeScript types
json2ts -i ./schemas/user.json -o ./types/user.ts

# Convert an entire directory of JSON Schemas
json2ts -i ./schemas -o ./types --bannerComment "// Auto-generated by json2ts"

    Frequently Asked Questions (FAQs)

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