What this does

Generates C# classes (POCOs) with auto-properties from a JSON sample, inside the namespace you choose. JSON keys are converted to PascalCase property names, and nested objects become separate partial classes.

Example

Input

{
  "id": 42,
  "name": "Ada",
  "verified": true,
  "tags": [
    "admin",
    "dev"
  ],
  "orders": [
    {
      "sku": "A1",
      "qty": 2
    },
    {
      "sku": "B2",
      "qty": 1,
      "note": "gift"
    }
  ]
}

Output with default options

namespace Example
{

    public partial class Root
    {
        public long Id { get; set; }
        public string Name { get; set; }
        public bool Verified { get; set; }
        public string[] Tags { get; set; }
        public Order[] Orders { get; set; }
    }

    public partial class Order
    {
        public string Sku { get; set; }
        public long Qty { get; set; }
        public string? Note { get; set; }
    }
}

How values are mapped

Whole numbers become long, other numbers double (or decimal if you choose), strings string, booleans bool.
Arrays become T[] or List<T>, your choice.
Values that are sometimes null or missing become nullable (string?, long?).
ISO 8601 timestamps become DateTimeOffset and UUID strings become Guid when date detection is on.

Options

Pick System.Text.Json or Newtonsoft.Json. WithTypes only turned off the output adds the matching[JsonPropertyName] or [JsonProperty] attributes, plusFromJson and ToJson helpers and converters, so the original key names survive the PascalCase rename.

Things to know

System.Text.Json matches property names case-sensitively by default, so keep the attributes (turn Types only off) if your JSON uses camelCase keys and you have not configured a naming policy. A sample with several objects gives the best nullability.

Privacy

Generation runs in a Web Worker in your browser. The JSON is never uploaded.

JSON to C# Class Converter