Does it handle nested objects and arrays?

Yes. Nested JSON objects become separate named Rust structs, and arrays become Vec types. Arrays of objects merge every field seen across all elements into one struct so no field is missed.

How are numbers typed?

Whole numbers are generated as i64 and numbers with a decimal point as f64, a common default for structs deserialized with serde_json.

What happens to camelCase or kebab-case keys?

JSON keys are converted to snake_case for the Rust field name (for example userId becomes user_id). If the converted name differs from the original key, a #[serde(rename = "...")] attribute preserves the exact JSON key.

What crates do I need?

The generated code assumes serde (with the derive feature) and, when a field can be null, serde_json for the Value type. Add both to your Cargo.toml dependencies.

Is my JSON sent to a server?

No. Parsing and struct generation both run in your browser with plain JavaScript. Nothing is uploaded anywhere.

What does it do with null values?

A field that is null in the sample JSON is typed as Option since Rust cannot infer a concrete type from a single null value.

JSON to Rust

Paste JSON and instantly get matching Rust struct definitions with serde derives, nested structs, and Vec types.

JSON Input

Root struct name

Derive Clone

Rust Structs

Nested objects become their own named struct, since Rust has no anonymous struct syntax.

Copied!

Summary

This tool converts sample JSON into Rust struct definitions ready for a serde-based project. It walks the JSON tree, infers a Rust type for every value, merges the fields of arrays of objects into a single struct, and writes serde derive attributes plus per-field rename tags so serde_json can parse the original JSON back into the same shape. Nested objects become their own named structs, since Rust has no anonymous struct syntax the way Go does.

How it works

Paste JSON into the input box, or click "Load Sample" to try it with example data.
Set a root struct name for the top-level type.
The Rust struct definitions render on the right as you type.
Nested objects become separate named structs; arrays of objects merge their fields into one struct.
Toggle "Derive Clone" if your code needs to clone the generated structs.
Click "Copy Rust Code" to copy the generated code to your clipboard.

Use cases

Bootstrap Rust structs for a REST API client from a sample response.
Type a webhook payload before writing the handler.
Generate structs from third-party API documentation JSON.
Check how serde will map a JSON shape before writing code by hand.
Speed up prototyping Rust services that consume external JSON.

Frequently Asked Questions

Last updated: 2026-07-13 · Reviewed by Nham Vu