Convert JSON to Kotlin Data Class Online

Convert JSON into a Kotlin data class, right in your browser.

▸JSON▸Kotlin

data class Root(
    val id: Int,
    val name: String,
    val active: Boolean
)

🔒 100% client-side — no data sent

Automatically generate Kotlin data classes from any JSON, with types correctly inferred. Everything runs 100% in your browser, keeping your code and data fully private.

What is it for?

▸ Create Kotlin models to deserialize a REST API response
▸ Generate data classes for an Android app using Gson or Moshi
▸ Save time by avoiding manually writing dozens of properties
▸ Quickly prototype a data layer from a JSON example

FAQ

How do I generate a Kotlin data class from JSON?

Paste your JSON into the tool and the matching Kotlin data classes are generated instantly with the correct types.

Does the tool handle nested objects and arrays?

Yes, nested objects become separate data classes and arrays are converted into typed Lists.

Are nullable fields supported?

Null values in the JSON are detected and the corresponding Kotlin type is marked nullable with a question mark.

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