JSON to Kotlin

What is JSON?

JSON (JavaScript Object Notation) is a lightweight format for storing and exchanging data. It’s commonly used in web and mobile applications to transfer structured information between clients and servers. JSON is easy to read and write for both humans and machines, making it ideal for APIs.

What is Kotlin?

Kotlin is a modern, concise, and statically typed programming language developed by JetBrains. It runs on the Java Virtual Machine (JVM) and is officially supported for Android development by Google. Known for its null safety, interoperability with Java, and minimal boilerplate, Kotlin is perfect for converting JSON into structured data classes.

How to Use the JSON to Kotlin Converter?

• Enter your JSON in the top text area labeled "Input". You can type or paste any valid JSON structure.
• Make sure the "Auto Update" checkbox is enabled (it's on by default) so the conversion happens automatically as you type.
• If you prefer manual control, you can uncheck Auto Update and then click the "JSON to Kotlin" button to generate the code.
• Your converted Kotlin data classes will appear instantly in the "Output" section below.
• Use the icons on the side to:
  • Copy content
  • Clear the fields
  • Format or reset input/output (hover over icons for tooltip descriptions)

Which library should I use for data parsing in Kotlin?

After converting JSON to Kotlin data classes, you’ll need a library to parse JSON into those classes. Here are popular choices:

• Kotlinx.serialization: Official Kotlin library, perfect for multiplatform projects and modern Kotlin apps.
• Moshi: Great for Android, with strong Kotlin support and minimal setup.
• Gson: Popular and easy to use, widely adopted in Android projects.
• Jackson: Powerful option for larger or complex applications by FasterXML.

For most Kotlin projects, kotlinx.serialization or Moshi are excellent choices.

Use Cases of this JSON to Kotlin Converter

• Convert JSON to Kotlin data class for Android apps.
• Generate JSON Kotlin models for backend systems.
• Simplify API integration with ready-to-use Kotlin classes.
• Automate JSON to Kotlin data class creation for faster development.

Frequently Asked Questions (FAQs)

Can I rename the root class name?

Yes, some versions of the tool let you customize the root Kotlin data class name. Look for an input field labeled “Class Name” if available.

Does the tool support annotations like @SerializedName?

This version doesn't show options for annotations directly. If needed, you can manually add @SerializedName("jsonKey") for libraries like Gson or Moshi.

What happens if the JSON is invalid?

If your input has syntax errors, the tool won’t generate Kotlin output. Make sure your JSON is properly formatted with double-quoted keys and correct commas.

Is there a way to format or beautify the JSON before converting?

Yes, you can use the formatting icon next to the input box to automatically clean up and format your JSON before running the conversion.

Does this tool work offline?

Most of the logic runs in your browser after the page loads, but for best results and updates, it’s recommended to use it with an internet connection.