Data ClassesGson AnnotationsNullable Support

How It Works

1

Paste JSON

Paste your JSON data in the input.

2

View Classes

See generated Kotlin data classes.

3

Copy Code

Copy the Kotlin code to your project.

Frequently Asked Questions

Does it generate SerializedName annotations?
Yes. When property names differ from JSON keys, @SerializedName annotations are automatically added for Gson compatibility.
Are nullable types handled?
Yes. Null values in the JSON input are converted to Any? nullable types in Kotlin.
Does it support nested objects and arrays?
Yes. Nested objects become separate data classes, and arrays become List<Type> with proper type inference.
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About JSON to Kotlin

JSON to Kotlin is a free, browser-based utility designed to make this task as quick and frictionless as possible. The goal was to keep the path from "open the page" to "get the result" as short as possible. No mandatory account, no cookie wall, no upsell at every step. Like everything else in the utility collection, it is free, ad-light, and works on mobile as well as desktop.

When you'd reach for JSON to Kotlin

  • You need to handle a one-off task right before a meeting and don't have time to install anything.

    Anyone working remotely on a borrowed or restricted machine.

    Open the page, get the result, paste it into your doc — under a minute.

  • You're on a public or shared machine and don't want to leave traces of what you're working on.

    Travelers, contractors, anyone working from a friend's computer.

    Nothing is uploaded, nothing persists if you're not signed in.

  • You're cleaning up a folder of files that accumulated over a project and need to standardize them.

    Designers, writers, and developers wrapping up deliverables.

    Drop each file in, copy the output, move on.

  • You're hitting the daily limit of a paid SaaS and need a backup option for a single quick job.

    Marketers and ops people whose primary tool is metered.

    Stay productive without burning credits.

Frequently asked about JSON to Kotlin

Are my files uploaded to a server when I use JSON to Kotlin?
JSON to Kotlin processes everything in your browser using local APIs. Your files never leave your device.
What browsers does JSON to Kotlin support?
Every modern browser released in the last three years: Chrome, Firefox, Safari, Edge, Brave, Opera.
Will JSON to Kotlin change my original file?
Never. JSON to Kotlin only reads your input file and produces a new output file.
Do I need to create an account to use JSON to Kotlin?
No. JSON to Kotlin works without any signup. We only ask for an email if you decide to subscribe to a paid plan.
Does JSON to Kotlin work on mobile?
Yes, JSON to Kotlin is fully responsive and tested on iOS Safari and Android Chrome.

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