jsonpost
Code Generation

JSON to Kotlin Data Class Generator

Turn JSON into Kotlin data classes with nullable types and serialization annotations.

Runs entirely in your browser — your data never leaves your device.

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How to use this tool

  1. 1Paste your JSON sample into the editor.
  2. 2Set the root class name.
  3. 3Copy the generated Kotlin data classes.

Frequently asked questions

Are nullable types inferred?
Yes. Fields that may be absent or null are typed as nullable in the generated Kotlin.
Is it suitable for Android?
Yes. The data classes work well with Retrofit and kotlinx.serialization for consuming REST APIs.
Is my data uploaded to a server?
No. Every tool on JSONPost runs entirely in your browser using JavaScript. Your JSON never leaves your device, so it is safe to use with private or sensitive data.

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