JSON to Code — TypeScript, Go, Rust, Python & more
Paste JSON and generate type definitions in TypeScript, Go, Rust, Python, Java, Kotlin, Swift or C# — pick the language from a dropdown. Free, no upload.
🔒 Generated in your browser — your JSON is never uploaded.
Turn JSON into typed code, in any language
Paste a JSON sample, pick your target language, and get ready-to-paste type definitions — nested
objects become nested types, arrays become typed lists, and field types are inferred from the values.
Supports TypeScript interfaces, Go structs (with json tags),
Rust structs (serde), Python dataclasses, Java classes
(Jackson @JsonProperty), Kotlin data classes (kotlinx.serialization),
Swift Codable structs and C# classes (System.Text.Json). Wherever a key has
to be renamed to be a legal identifier — first_name to firstName — the original key
is kept in the annotation or tag that language uses, so the code decodes the JSON it was generated from.
TypeScript quotes an awkward key rather than renaming it; Python dataclasses have no such annotation, and are
the one target where a renamed field no longer matches its key.
Everything runs in your browser — your JSON is never uploaded.
Frequently asked questions
Which languages are supported?
TypeScript, Go, Rust, Python (dataclasses), Java (Jackson), Kotlin (kotlinx.serialization), Swift (Codable) and C# (System.Text.Json). Choose the target from the Language dropdown; the same JSON generates code for any of them.
What happens to a JSON key that is not a valid identifier?
It is renamed to the idiomatic form for the language — first_name becomes firstName in Java and Kotlin, FirstName in C# — and the original key is recorded so the generated code still decodes: a Jackson @JsonProperty in Java, a kotlinx.serialization @SerialName in Kotlin, a [JsonPropertyName] attribute in C#, a json struct tag in Go, #[serde(rename = "…")] in Rust and a CodingKeys enum in Swift. TypeScript quotes the key instead. Reserved words are handled per language too — a trailing underscore in Java and Python, backticks in Kotlin and Swift, a raw identifier in Rust.
Does it handle nested objects and arrays?
Yes. Nested objects become nested type definitions and arrays become typed collections, with names derived from the field and root name you set.
Is my JSON uploaded anywhere?
No. Parsing and code generation run entirely in your browser, so sensitive payloads never leave your device.