JSON to Kotlin Converter
ConvertersGenerate Kotlin data classes from a JSON object instantly in your browser. Powered by quicktype-core. Clean data class output. UML class diagram view. Client-side.
JSON →
Kotlin
JSONjson
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Kotlinkotlin
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Input: 315 chars
About JSON to Kotlin Converter
The JSON to Kotlin converter uses `quicktype-core` with `framework: just-types` to generate Kotlin `data class` definitions (no Klaxon or runtime dependencies). A post-processor normalises constructor formatting. Output is prettified with js-beautify. The UML class diagram panel shows the inferred class hierarchy.
Features
- ✓Powered by quicktype-core with just-types (no Klaxon)
- ✓Generates idiomatic Kotlin data classes
- ✓Normalised constructor formatting for readability
- ✓Post-processed and prettified with js-beautify
- ✓UML class diagram view shows the inferred class hierarchy
- ✓Handles nested objects → nested data classes
- ✓Handles arrays → List<T> properties
- ✓Nullable fields use T? type annotations
- ✓Download generated Kotlin as a .kt file
- ✓Copy output to clipboard in one click
- ✓Web Worker processing — never blocks the UI
- ✓100% client-side — data never leaves your browser
Common Use Cases
- Generating Kotlin data classes from JSON API responses for Android apps
- Creating Kotlin model classes from JSON payloads for Ktor services
- Scaffolding Kotlin DTOs from JSON configuration files
- Reverse-engineering JSON to Kotlin types for Gson or Moshi serialization
Frequently Asked Questions
QDoes the output work with Gson and Moshi?
Yes — the generated data classes are plain Kotlin and work with both Gson and Moshi (with no extra annotations needed for simple cases).
QIs my data sent to a server?
No. quicktype-core runs in a Web Worker inside your browser.