JSON to Java Converter
Convert JSON to Java POJO classes for Java development
JSON Input
Java Output
What is JSON to Kotlin Converter?
Need to generate Kotlin data classes from your JSON (JavaScript Object Notation) data? This tool does that instantly. Perfect for Kotlin developers working with Android, Spring, or Kotlin/JVM who need to deserialize JSON into strongly-typed Kotlin objects. Generate data classes, properties, and type definitions automatically.
According to Kotlin documentation, data classes make JSON processing seamless. Our converter analyzes your JSON structure and generates proper Kotlin data classes. First, validate your JSON using our JSON Validator, then convert it to Kotlin. You can also format your JSON with our JSON Formatter first if needed.
Everything happens in your browser – your JSON never leaves your computer. Convert, download, and use your Kotlin data classes right away.
What Makes This Tool Different
Automatic Data Class Generation
We analyze your JSON structure and automatically generate Kotlin data classes. JSON objects become data classes, arrays become List<T>, everything gets proper Kotlin types.
Data Class Support
Generate Kotlin data classes for cleaner, more concise code. Data classes automatically generate equals(), hashCode(), toString(), and copy() methods.
Nullable Types
Use nullable types for properties that might be null. Perfect for Kotlin's null safety system and safe JSON decoding.
File Upload Support
Got a big file? Just upload it. Works great for converting those massive JSON configs or data files without copy-pasting.
Download Kotlin
One click to download your Kotlin file. Drop it into your Kotlin project and start using it. Perfect for Android, Spring, or Kotlin/JVM applications.
Clean Code Output
The generated Kotlin code is clean and well-formatted. Data classes are properly named, properties are typed correctly, and the code follows Kotlin conventions.
How It Works
Paste or Upload JSON
Paste your JSON into the left editor, or click "Upload" to load a file. The JSON should be valid – use our JSON Validator first if you're not sure. You can also click "Sample" to see an example.
Configure Options
Set your data class name, package name, and choose whether to use data classes or nullable types. These settings customize the generated Kotlin code to match your project's conventions.
Download or Copy
Click "Download" to save the Kotlin file, or "Copy" to copy it to your clipboard. The Kotlin code is ready to use in your project. Drop it into your Kotlin project and start using it.
When You'd Actually Use This
Android Development
Generate Kotlin data classes from JSON API responses for Android apps. Create models for REST APIs or JSON-based configurations. Perfect for Android's JSON processing needs.
Spring Applications
Create Kotlin data classes from JSON data for Spring Boot apps. Generate data models for JSON-based APIs or configurations. Perfect for Spring's Kotlin support.
Kotlin/JVM
Generate Kotlin data classes from JSON data for Kotlin/JVM applications. Create data models for JSON-based APIs or configurations. Perfect for Kotlin server-side development.
Code Generation
Generate Kotlin code from JSON data structures. Perfect for creating data models, DTOs, or entity classes from JSON schemas or API responses.
Common Questions
Is my JSON data stored?
Nope. Everything happens right in your browser. Your JSON never leaves your computer – we don't even see it.
How are JSON objects handled?
JSON objects become Kotlin data classes. Properties become data class properties, and nested objects become nested data classes or references. Arrays become List<T>.
Can I use the generated Kotlin code?
Yes. The generated Kotlin code is valid and ready to use. Drop it into your Kotlin project and start using it. You may want to review and refine the data classes for your specific use case.
What about JSON serialization?
The generated Kotlin data classes work with kotlinx.serialization, Gson, or Jackson for JSON serialization. You may need to add serialization annotations for custom property names.
Does it work with large JSON files?
Yep. Since everything happens in your browser, it depends on your device. Small to medium JSON structures convert instantly. Really huge structures might take a few seconds.
What Kotlin version is supported?
The generated code works with Kotlin 1.0 and later. It uses standard Kotlin features and follows Kotlin conventions for maximum compatibility.
Other JSON Tools You Might Need
Conversion is just one JSON task. Here are other tools that work well together:
Need to learn more about JSON? Check out the official JSON.org website or the comprehensive guide on MDN. For Kotlin, check out the official Kotlin documentation.