JSON to Rust Struct Generator (serde)

How to convert JSON to Rust structs

Paste your JSON into the editor.
Open the Code tab and choose Rust.
Copy the structs and deserialize with serde_json::from_str.

serde attributes explained

Rust field names are snake_case, so a key such as userId becomes user_id with #[serde(rename = "userId")]. Optional and nullable fields become Option<T> with default and skip_serializing_if, so missing keys parse and None values are omitted when serializing.

Types used

Strings are String, whole numbers i64, decimals f64 and booleans bool. Arrays become Vec<T>. Values whose type cannot be pinned down, such as mixed types or bare null, fall back to serde_json::Value.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data format that is easy for people to read and for machines to parse. It is the de facto standard for web APIs, configuration files and data exchange between services. A JSON document is built from just six value types: objects, arrays, strings, numbers, booleans and null.

{
  "name": "Ada",
  "age": 36,
  "admin": true,
  "skills": ["math", "code"],
  "address": { "city": "London" },
  "manager": null
}

JSON is stricter than JavaScript object literals: keys and strings must use double quotes, trailing commas are not allowed and comments are not part of the specification (RFC 8259).

Why format JSON?

APIs usually return minified JSON on a single line, which is efficient for machines but unreadable for people. Formatting (also called pretty printing or beautifying) adds consistent indentation and line breaks so that you can scan the structure, spot mistakes and review changes. Minifying does the opposite and strips whitespace to reduce size.

Frequently asked questions

Do I need extra crates?

Yes: serde with the derive feature and serde_json, for example cargo add serde --features derive and cargo add serde_json.

Is my JSON uploaded to a server?

No. Parsing, validation, formatting, diffing and code generation all run inside your browser, using a Web Worker. Your data is never sent to any server, which makes the tool safe for API responses, configuration files and other sensitive payloads.

How large a JSON file can I open?

Files of 20 MB and more work. Parsing happens off the main thread and the tree view is virtualized, so only the rows you can see are rendered. The editor switches to a lighter mode for very large documents.

What is the difference between formatting and minifying JSON?

Formatting (pretty printing) adds line breaks and indentation so people can read the data. Minifying removes all optional whitespace to make the payload as small as possible for network transfer or storage. Both produce identical data.

JSON to Rust