JSON to C# Class Converter (System.Text.Json)

Convert JSON to C# classes with System.Text.Json [JsonPropertyName] attributes, PascalCase properties, List<T> for arrays, and optional namespace. Works in .NET 6 / 7 / 8 / 9. 100% local.

Last updated: July 20, 2026

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Paste JSON to generate C# classes with System.Text.Json [JsonPropertyName] attributes, PascalCase properties, List<T> for arrays, and optional namespace. Works in .NET 6 / 7 / 8 / 9. 100% local.

Root class:Namespace:

JSON Input

135 chars · 7 lines

C# Output (System.Text.Json)

using System.Collections.Generic;
using System.Text.Json.Serialization;

public class Profile
{
    [JsonPropertyName("age")]
    public long Age { get; set; }

    [JsonPropertyName("city")]
    public string City { get; set; }
}

public class User
{
    [JsonPropertyName("id")]
    public long Id { get; set; }

    [JsonPropertyName("name")]
    public string Name { get; set; }

    [JsonPropertyName("active")]
    public bool Active { get; set; }

    [JsonPropertyName("roles")]
    public List<string> Roles { get; set; }

    [JsonPropertyName("profile")]
    public Profile Profile { get; set; }
}

Tips & Best Practices

▸For Newtonsoft.Json, replace [JsonPropertyName("x")] with [JsonProperty("x")] and swap the using directive.
▸For C# records, replace 'public class Foo { … }' with 'public record Foo(Type1 F1, …);' — the property types are already right.
▸Enable STJ source generation for AOT / trim-safe scenarios — the generated classes are compatible.

Frequently Asked Questions

Which JSON library is the output tuned for?

System.Text.Json — the stdlib serializer in .NET 6+. [JsonPropertyName("...")] annotations preserve the original JSON key names when the C# property name differs.

How do I switch to Newtonsoft.Json?

Replace `[JsonPropertyName("x")]` with `[JsonProperty("x")]` and swap the `using System.Text.Json.Serialization;` import for `using Newtonsoft.Json;`. Everything else is drop-in.

Can I generate C# records instead of classes?

The current output emits classes with get/set properties for maximum tooling compatibility. For records, replace `public class Foo { … }` with `public record Foo(Type1 Field1, …);` — the property types are already correct.

Is my JSON uploaded anywhere?

No. All conversion happens locally in your browser.

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JSON to C# Class Converter (System.Text.Json)

Tips & Best Practices

Frequently Asked Questions

Comments

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