JSON to C# Class Generator
Turn any JSON payload into strongly-typed C# classes with System.Text.Json attributes — perfect for .NET APIs.
About JSON to C# Class Generator
The JSON to C# Class Generator converts a JSON document into strongly-typed C# model classes. It walks the JSON tree, detects nested objects and arrays, and emits one class per type with properties matching the JSON keys — ready to paste into your .NET solution.
A representative sample lets the generator infer primitive property types, collections and nested models. Naming and serializer-attribute options reduce repetitive setup when consuming a new endpoint with System.Text.Json or Newtonsoft.Json.
Generation happens in the browser, which matters when the sample payload comes from a private endpoint. You still own the modelling decisions: rename awkward keys, tighten nullability and replace guessed numeric types with the enums or value objects your domain actually uses.
Prefer a complete sample that includes nested objects, empty arrays and null fields. Sparse examples often generate non-nullable properties that fail later when the real API omits those keys.
How JSON to C# Class Generator works in practice
- 1Paste a representative JSON sample into the input area.
- 2Set the root class name (for example, "OrderResponse").
- 3Pick options: PascalCase properties, System.Text.Json or Newtonsoft.Json attributes.
- 4Click "Generate" and copy the produced classes into your solution.
- 5Review property types and nullability against the API docs before committing.
Jobs this tool is built for
- Create response DTOs while integrating a documented REST endpoint into a .NET application.
- Turn a saved webhook example into typed models for a handler and its tests.
- Generate nested classes from a complex configuration sample before adding validation.
- Compare inferred types across multiple API examples to find optional or inconsistent fields.
What you can do here
- Detects nested objects, arrays, dates and primitives
- Optional serializer attributes for System.Text.Json or Newtonsoft.Json
- Configurable naming conventions
- One class per nested object type
- Output compatible with .NET 6 and newer
Limits and honest caveats
- Generation is local and does not upload the sample, but remove real credentials and personal data before saving generated code or sharing screenshots.
- Inference only sees values present in the sample — missing optional fields will not appear as properties.
- Review nullable reference types, integer ranges and date formats before using generated models in production.
Common questions about JSON to C# Class Generator
Can I generate records instead of classes?
Currently only classes are generated. You can convert them to records manually if your project prefers that style.
Does it handle polymorphic JSON?
Not automatically — polymorphic types usually need a hand-written converter or discriminator mapping.
Why should I use a representative sample?
Inference only sees values present in the sample. Include examples of nested objects, arrays, nulls and optional variants, then review the resulting nullable and numeric types.
Should generated classes be used without review?
No. Check names, nullability, integer ranges, date handling and required fields against the API contract before relying on them in production.
Which serializer attributes should I pick?
Choose System.Text.Json attributes for modern ASP.NET Core defaults, or Newtonsoft.Json if your project still uses Json.NET.
This page was written by the ToolSink team to explain how JSON to C# Class Generator works on this site — it is not syndicated, scraped, or spun from another publisher. How we write tool guides · Site updates · About ToolSink.
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