One document, or several samples as JSON Lines.
Options for C#

Convert JSON to C# classes

Paste a JSON sample and get C# records (or classes with properties): string, long, double, bool, List<T>, nested types, nullable types for fields that are null or missing in some records, and [JsonPropertyName] on every member so the original keys round-trip with System.Text.Json.

Deserialize with JsonSerializer.Deserialize<Root>(json). It runs entirely in your browser.

Need a different language? See all JSON-to-code converters.

Other languages

JSON to TypeScript interfacesJSON to Kotlin data classes

JSON to C# Class Converter — frequently asked questions

Records or classes?
Pick either under Options. Positional records are concise and immutable; classes with { get; set; } properties suit older code and Newtonsoft.Json (swap the attribute for [JsonProperty]).
What if some records have fields that others don't?
Every item of every array and every sample is read, not just the first. A field missing from some records comes out optional, a field holding two kinds of value becomes a union (or the language's any-value type), null beside a value makes it nullable, and a list of records at the top level gets an item type plus an alias for the list. Paste several samples as JSON Lines, one per line, and they're merged the same way.
Is my JSON uploaded anywhere?
No. Parsing and code generation run entirely in your browser with JavaScript — your JSON never leaves your device, so it's safe to paste API responses and other sensitive payloads. It's free with no sign-up.

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