Is my JSON data uploaded to a server?

No. Everything runs entirely in your browser with JavaScript. Nothing is sent over the network, which makes the tool safe for sensitive data.

When is a CodingKeys enum generated?

Only when at least one JSON key differs from its camelCase Swift name (snake_case, dashes…). Otherwise the synthesized Codable conformance is enough and no enum is emitted.

How are null values represented?

Fields that are null (or mixed-type arrays) use a small self-contained JSONValue enum appended to the output, so the generated code compiles without external dependencies.

JSON to Swift Codable Structs

JSON to Swift Codable Structs — Free Online Tool

Generate Swift Codable structs from sample JSON instantly in your browser. Free, private and offline-friendly: your data never leaves your device.

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Root name

JSON input

Swift output

Why convert JSON to Swift?

Modeling API payloads with Swift structs by hand takes time. Paste a sample JSON document above and receive Codable structs ready to drop into your iOS or macOS project, nested objects included.

How it works

The converter parses your JSON locally and emits one struct … : Codable per object. Integers map to Int, floats to Double, arrays to [T]. Properties are camelCased and a CodingKeys enum restores the original keys when they differ. Toggle the var option for mutable properties, and rename the root type with the Root name field.

Frequently asked questions

Is my JSON data uploaded to a server?: No. Everything runs entirely in your browser with JavaScript. Nothing is sent over the network, which makes the tool safe for sensitive data.
When is a CodingKeys enum generated?: Only when at least one JSON key differs from its camelCase Swift name (snake_case, dashes…). Otherwise the synthesized Codable conformance is enough and no enum is emitted.
How are null values represented?: Fields that are null (or mixed-type arrays) use a small self-contained JSONValue enum appended to the output, so the generated code compiles without external dependencies.