JSON to Kotlin Data Class Converter

Paste your JSON into OpenToolLab's JSON to Kotlin converter and click Generate code. The tool emits @Serializable data classes with @SerialName where needed, typed properties, defaults, and nested classes ready for kotlinx.serialization.

Add kotlinx.serialization to your project, decode with Json { ignoreUnknownKeys = true }.decodeFromString<MyModel>(json), and use the generated data class. This converter generates the @Serializable model for you.

For Java, use Gson or Jackson with a JSON to Java tool. OpenToolLab focuses on Kotlin data classes, which are the idiomatic choice for modern Android development; switch this converter's language tab if you need Dart, TypeScript, or Swift instead.

Decode the JSON string with kotlinx.serialization: Json.decodeFromString<MyModel>(json). The @Serializable data class generated by this converter defines how each key maps to a typed property.

Use File("data.json").readText() or, on Android, read assets via context.assets. Then decode the text with kotlinx.serialization using the data class this converter generates.

C# uses Newtonsoft.Json or System.Text.Json. OpenToolLab's JSON to Kotlin converter targets Kotlin; the same JSON sample can be converted to TypeScript, Dart, or Swift here, and JSON to C# is a separate ecosystem tool.

Yes — paste the contents of your JSON file into the converter and generate a Kotlin data class. The same sample can also be switched to TypeScript, Dart, or Swift output without re-pasting.

{} is an empty JSON object. If the converter meets an empty object it generates a minimal data class. Paste a richer sample to get fully typed properties and nested models.

In Java you typically use Gson or Jackson to deserialize into POJOs. Kotlin developers use kotlinx.serialization data classes, which this converter generates automatically from your JSON sample.

JSON is the standard text format for exchanging structured data between systems — APIs, configs, and storage. Its purpose here is to describe the shape of your data so a converter can generate matching Kotlin data classes.

Load the file from assets or resources, read it as a string, then decode with kotlinx.serialization: Json.decodeFromString<MyModel>(text). The @Serializable model this converter generates makes the decode type-safe.

Use Gson or Jackson to map JSON to POJOs. If you are on Kotlin (the modern Android standard), use kotlinx.serialization with data classes — which is exactly what this JSON to Kotlin converter produces.