JSON to Code

Why generate types from JSON?

Type safety prevents an entire class of runtime bugs. When you consume an API, the response is untyped JSON — a plain object with no guarantees about its shape. By generating typed interfaces, structs, or classes from a sample response, you get compile-time checks, editor autocompletion, and self-documenting code. Instead of guessing field names or manually writing type definitions, paste the JSON and let the tool do the tedious work.

How it works

The tool parses your JSON into a type tree — an internal representation of every field, its inferred type (string, integer, float, boolean, null, array, or nested object), and its original key name. It then walks this tree and emits idiomatic code for the selected language: correct naming conventions (camelCase, snake_case, PascalCase), serialization annotations (Go struct tags, Rust serde attributes, Java/Kotlin @JsonProperty, C# [JsonPropertyName]), and necessary imports. Everything runs client-side in JavaScript — your JSON never leaves your browser.

JSON to TypeScript vs JSON to Go

TypeScript uses interface declarations with camelCase field names and a unified number type for both integers and floats. Go uses exported struct types with PascalCase fields and json:"key" struct tags for serialization, and distinguishes between int and float64. Both outputs are ready to paste — TypeScript into a .ts file, Go into a .go file — and will work with their respective JSON decoders out of the box.

Supported languages

• TypeScript — interface or type aliases with optional export
• Go — exported struct types with json:"key" struct tags
• Python — @dataclass or TypedDict with type hints (3.10+ syntax)
• Rust — struct with #[derive(Deserialize, Serialize)] and serde attributes
• Swift — struct: Codable with CodingKeys enum
• Java — POJO with getters/setters and @JsonProperty
• Kotlin — data class with @JsonProperty
• C# — class with { get; set; } properties and [JsonPropertyName]
• Dart — class with fromJson() / toJson() factory constructors

Frequently asked questions