Tool Spotlight

JSON to Kotlin Data Class Converter

Paste or fetch JSON data and generate clean Kotlin data classes instantly.

Upload JSON

🔽 JSON Input

JSON

🧾 Kotlin Data Class

KOTLIN

Instant Conversion

Convert your data in real-time as you type. No delays, no waiting.

100% Private

All processing happens in your browser. Your data never leaves your device.

Always Free

No hidden fees, no premium plans. All features are completely free forever.

Convert JSON to Kotlin Data Class Online – Free JSON to Kotlin Converter

Convert JSON to Kotlin data classes instantly. Generate clean, null-safe Kotlin models with proper type inference, nested object support, and List handling. Free online JSON to Kotlin data class generator built for Android developers and Kotlin backend engineers.

What Is a JSON to Kotlin Data Class Converter?

A JSON to Kotlin Data Class Converter is an online tool that transforms structured JSON data into strongly typed Kotlin data classes. It automatically maps JSON keys to Kotlin properties, generates nested data classes for objects, converts arrays into List types, and ensures proper type inference. The entire conversion happens in your browser, keeping your data secure and private.

Instant JSON to Kotlin Data Class Generation

Automatically generate Kotlin data classes from JSON in seconds with correct structure and formatting.

Accurate Type Inference & Null Safety

JSON types are mapped to proper Kotlin types such as String, Int, Double, Boolean, and List with optional nullable support.

Supports Nested Objects & Arrays

Nested JSON objects automatically generate separate Kotlin data classes, while arrays are converted into List<T> types.

Why Use an Online JSON to Kotlin Converter?

Speed Up Android Development

Avoid manually writing model classes. Instantly generate Kotlin data classes for Android apps using API responses.

Reduce Human Errors

Manual model creation often leads to type mismatches. Automated conversion ensures correct data mapping.

Perfect for API Integration

Convert REST API JSON responses into ready-to-use Kotlin models for Retrofit, Ktor, or other networking libraries.

Secure & Browser-Based Tool

Your JSON data is processed entirely in your browser with no server uploads, ensuring privacy and security.

When Should You Convert JSON to Kotlin Data Class?

Integrating REST APIs in Android

When consuming API responses in Android apps, convert JSON into Kotlin data classes for structured model handling.

Backend Development with Kotlin

Generate Kotlin models from JSON schemas for backend services built with Ktor or Spring Boot.

Working with Complex Nested JSON

Convert deeply nested JSON structures into organized Kotlin classes automatically.

Rapid Prototyping & MVP Development

Quickly create data models when building MVP apps or testing API integrations.

Learning & Code Generation

Developers learning Kotlin can better understand data modeling by converting real JSON examples into data classes.

How to Convert JSON to Kotlin Data Class Online

Paste Your JSON Data

Copy JSON from an API response, file, or backend service and paste it into the input editor.

{
  "id": 1,
  "name": "Sourav",
  "isActive": true
}

Click convert to automatically generate properly structured Kotlin data classes.

The tool automatically generates a TypeScript interface in the right panel. It detects types, handles nested objects, and creates proper interface names.

data class RootModel(
  val id: Int,
  val name: String,
  val isActive: Boolean
)

Copy & Use in Your Project

Copy the generated Kotlin data classes and use them directly in your Android or backend project.

Pro Tips

•Ensure your JSON is valid before converting.
•Use consistent key naming in JSON for cleaner Kotlin properties.
•Enable nullable types if API fields may return null.
•Rename the root class to match your project naming conventions.
•Use the generated models with Retrofit, Moshi, Gson, or Kotlinx Serialization for seamless API parsing.

Frequently Asked Questions

Everything you need to know about JSONtoAll tools.

What is a JSON to Kotlin Data Class Converter?

A JSON to Kotlin Data Class Converter is an online tool that transforms JSON data into structured Kotlin data classes. It automatically maps JSON fields to strongly typed Kotlin properties.

How do I convert JSON to a Kotlin data class?

Simply paste your JSON into the input editor and click convert. The tool instantly generates Kotlin data classes based on your JSON structure.

Does this tool generate Kotlin data classes?

Yes. The converter generates Kotlin data classes using the `data class` keyword with properly typed properties.

Does the tool support nested JSON objects?

Yes. Nested JSON objects are automatically converted into separate Kotlin data classes with proper references.

How are JSON arrays handled in Kotlin?

JSON arrays are converted into Kotlin `List<T>` types. If the array contains objects, a separate data class is generated for the item type.

Are nullable fields supported?

Yes. The tool can generate nullable types (e.g., `String?`, `Int?`) when JSON values may be null.

What Kotlin types are generated from JSON?

The converter maps JSON types to Kotlin types such as String, Int, Double, Boolean, List, and custom data classes for objects.

Can I use the generated Kotlin classes in Android projects?

Yes. The generated Kotlin data classes are fully compatible with Android development and can be used with libraries like Retrofit, Ktor, or serialization frameworks.

Does the tool support large JSON files?

Yes. The converter supports large and complex JSON structures while maintaining accurate type generation.

Is this JSON to Kotlin converter free to use?

Yes. The tool is completely free and works directly in your browser without requiring registration.

Does the tool validate JSON before converting?

Yes. Invalid or malformed JSON is detected automatically to prevent incorrect Kotlin class generation.

Can I convert a single JSON object?

Yes. A single JSON object will generate one root Kotlin data class with corresponding properties.

Are numeric values properly typed in Kotlin?

Yes. Numbers are automatically mapped to appropriate Kotlin numeric types such as Int or Double based on the JSON value.

Is my JSON data uploaded to a server?

No. The conversion happens entirely in your browser, ensuring complete privacy and security.

Can I customize the root class name?

Yes. You can typically specify a custom root class name before generating the Kotlin data classes.

Does the tool generate immutable properties?

Yes. By default, properties are generated using `val` to promote immutability in Kotlin.

What is the difference between JSON and Kotlin data classes?

JSON is a text-based data format commonly used in APIs, while Kotlin data classes are strongly typed models used in Kotlin applications to represent structured data.

Can I use the generated classes with Retrofit or Ktor?

Yes. The generated Kotlin models work seamlessly with Retrofit, Ktor, and other networking libraries.

Does the converter handle Boolean values correctly?

Yes. JSON true/false values are correctly mapped to Kotlin Boolean types.

Why should I use a JSON to Kotlin converter?

Using a converter saves development time, reduces manual coding errors, ensures proper type safety, and speeds up API integration in Android and Kotlin backend projects.

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