JSON to Kotlin Converter
Convert JSON to Kotlin data classes with nested models, nullable properties, and kotlinx.serialization, Moshi, or Gson annotations in your browser.
Loading tool...
What is JSON to Kotlin Converter?
JSON to Kotlin Converter is a browser-based developer tool that turns JSON samples into Kotlin data classes for Android apps, APIs, and backend projects.
Key Benefits
- Generate nested Kotlin models without writing repetitive boilerplate.
- Make optional API fields explicit with Kotlin nullable types.
- Add annotations for popular serialization libraries in one click.
- Keep API samples private because processing happens locally.
Common Use Cases
- •Create models from REST API response examples.
- •Prototype Android or Kotlin Multiplatform data classes.
- •Prepare DTOs for kotlinx.serialization, Moshi, or Gson projects.
- •Convert fixture JSON into readable Kotlin test models.
How to Convert JSON to Kotlin Data Classes
- Paste JSON: Paste a valid JSON object or array into the JSON Input panel.
- Choose options: Set the root class name and select nullable fields, camelCase, or serialization annotations as needed.
- Generate Kotlin: Click Generate Kotlin to infer types and create nested data classes.
- Copy or download: Review the generated code, then copy it or download the Kotlin .kt file.
Key Features
- Infer Kotlin primitive, collection, and nested object types from JSON.
- Generate readable data classes with safe names for Kotlin keywords.
- Choose nullable properties and camelCase field naming.
- Add kotlinx.serialization, Moshi, or Gson annotations and imports.
- Copy the generated code or download it as a .kt file.
Frequently Asked Questions
What does the JSON to Kotlin converter generate?
It generates Kotlin data classes from JSON objects, including nested classes, lists, primitive types, and optional serialization annotations.
Can it create nullable Kotlin properties?
Yes. Enable Make properties nullable to add Kotlin nullable markers to generated property types.
Which serialization libraries are supported?
You can generate imports and field annotations for kotlinx.serialization, Moshi, or Gson, or choose no annotations.
Is my JSON uploaded anywhere?
No. Parsing and code generation run entirely in your browser, so your JSON stays on your device.