⇄ Code & API Conversion

C# Class to JSON Converter

Generate sample JSON from C# classes, including nested classes, dictionaries, and lists.

Updated

Nested classes Dictionary support POCO friendly

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What this page sends

  • Your input: Processed in this tab and not sent to a server.
  • Share links: Share links put a Base64 copy of your input and output in the URL itself (after #d=). Anyone with the link can read it, so don't share a link that contains secrets.
  • Editor: On desktop screens the code editor (Monaco) is downloaded from cdn.jsdelivr.net; phones get a built-in lightweight editor instead.
  • Page load: Loading the page requests HTML, scripts and images from ByteKiln, fonts from Google Fonts, and sends Google Analytics page views, tool-usage events and catalog interactions (tool/category IDs, result status and whether a click followed search — never your input, output or search terms). Privacy & sharing

How the C# Class to JSON Converter Works

The ByteKiln C# to JSON converter reads your class definition and generates a representative JSON object with inferred sample values for each property. The class is parsed and the JSON generated in your browser.

How are values inferred?

Each .NET type gets a sensible placeholder: strings become "sample", integers become 0, booleans become false, DateTimes become an ISO timestamp, and Guids become a sample UUID string.

Nested and collection types

Known nested class types are recursively expanded into nested JSON objects. List<T> and arrays are represented as single-element arrays containing one instance of the inner type.

When to use this tool

Use it to generate example payloads for API documentation, Postman collections, or README examples — without manually writing JSON for every property in your model.

Limitations

  • The output is sample data from a declaration parser, not a serializer run: values are placeholders ("", 0, false, an ISO date), and nullable properties are shown as null.
  • Dictionaries become {} and custom generic wrappers such as Result<T> become an empty string, because there is no sample value to invent.
  • Only attributes it knows change the output: [JsonPropertyName], [JsonIgnore] and JsonStringEnumConverter. Newtonsoft settings, naming policies other than camelCase, and custom converters are not applied.
  • Types that aren't pasted can't be expanded; base classes are merged only when they are in the input too. Nesting is cut off after three levels.

FAQ

Short answers for the things developers usually ask before trusting a tool.

Does the ByteKiln C# to JSON converter support nested classes?

Yes. Known nested types are recursively expanded into example objects. Collections like List<T> and arrays become sample JSON arrays with one representative element.

Is this a replacement for JSON serialization at runtime?

No. The tool generates example JSON payloads based on your class structure. It is a design and documentation aid, not a runtime serializer like System.Text.Json or Newtonsoft.Json.

What property types does it recognize?

It maps common .NET types: string, int, long, double, decimal, bool, DateTime, Guid, and nullable variants. Unknown types are represented as empty objects.

Does my C# code get uploaded?

No. The class is parsed in your browser and is not sent to a ByteKiln server. If you press Share, the link itself carries a readable copy of your input, so don't share links that contain secrets.

Can I use this for API documentation?

Yes. Paste your request or response model and the tool produces a representative JSON example you can include in API specs, README files, or Postman collections.

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Want the background and worked examples? There's a longer write-up.

Read the C# → JSON guide

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