JSON to Kotlin Data Class
Generate Kotlin data classes from JSON instantly. High-performance tool for Android and KMP developers with support for SerializedName and @Serializable. Safe browser-side processing.
Complete JSON Conversion & Utility Tools
Below is a comprehensive list of JSON conversion and utility tools available on Tool Wizard Hub.
JSON → File & Data Formats
JSON → Programming Languages
JSON → Documents & Tables
JSON Utilities
Advanced JSON Tools
About JSON to Kotlin Data Class
The Ultimate Guide to JSON to Kotlin Data Class Generation
In modern mobile and backend development, Kotlin has become the language of choice due to its conciseness and safety. While JSON is the standard for network communication, Kotlin requires Data Classes to handle data models efficiently. Manually writing boilerplate for nested JSON structures is a repetitive task that invites bugs. Our JSON to Kotlin Converter automates this workflow, generating clean, production-ready data classes with support for null-safety, default values, and popular serialization libraries like KotlinX Serialization and Moshi.
Why Use a Kotlin Data Class Generator?
Kotlin data classes are powerful because the compiler automatically generates equals(), hashCode(), and copy() methods. Converting JSON to Kotlin models provides several key advantages for Android and KMP developers:
- Null Safety: Kotlin's type system helps you define which JSON fields are optional (nullable) and which are mandatory, reducing
NullPointerExceptions. - Immutability: Generate models using
valinstead ofvarto promote functional programming patterns and thread safety. - Library Integration: Generate classes that include annotations for Gson (@SerializedName), Moshi (@Json), or KotlinX Serialization (@SerialName).
- Speed: Transform complex API responses with dozens of nested levels into a full model hierarchy in milliseconds.
Smart Type Inference
Our tool analyzes JSON values to decide between Int, Long, Double, and String, ensuring your Kotlin types accurately represent the incoming data.
Nested Model Hierarchy
Deeply nested JSON objects are automatically extracted into separate data classes, promoting reusability and keeping your code organized according to SOLID principles.
Total Privacy & Security
We process your data entirely within your browser. No data is sent to our servers, making it safe for developers working with sensitive enterprise or financial APIs.
Technical Comparison: JSON vs. Kotlin Data Class
| Feature | JSON Structure | Kotlin Data Class |
|---|---|---|
| Nullability | Implicit | Explicit (String?) |
| Mutability | N/A (Static) | val (Immutable) / var |
| Standard Methods | None | copy(), toString(), equals() |
| Validation | No | Init blocks & Type safety |
How to Implement the Output in Your Project
Once you have generated your data classes, you can use them with your favorite networking library like Retrofit or Ktor. For example, using KotlinX Serialization:
@Serializable
data class UserProfile(
@SerialName("user_id") val id: Int,
val username: String,
val email: String? = null // Optional field
)
Frequently Asked Questions
Does this tool support KotlinX Serialization?
Yes! The generator can include the @Serializable and @SerialName annotations required for the modern KotlinX Serialization library used in KMP.
How does it handle snake_case JSON keys?
The tool follows Kotlin camelCase naming conventions for properties and automatically generates the necessary annotations to link them to snake_case JSON keys.
Are nullable types supported?
If the JSON contains a null value or you flag a property as optional, the generator will append a ? to the type (e.g., String?) to ensure Kotlin null-safety.
Can I convert Kotlin Data Classes back to JSON?
Absolutely. Kotlin serialization libraries make it easy to encode your objects back into JSON strings for API requests or local storage.