JSON to Swift

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based format used to store and exchange structured data. It’s easy to read, write, and parse, making it one of the most popular data formats in web and mobile development today.

JSON organizes data into key–value pairs and supports various types like strings, numbers, booleans, arrays, and nested objects. Here's a simple example:

{
 "name": "John",
  "age": 30,
  "skills": ["Swift", "Kotlin"]
}

Because of its simplicity and readability, JSON is commonly used in REST APIs and seamlessly supported in most programming languages, including Swift. Developers often convert JSON into native data models to make it easier to work with in their apps.

What is Swift?

Swift is Apple’s modern programming language used for building apps on iOS, macOS, watchOS, and tvOS. It's fast, safe, and easy to read, designed for both performance and developer productivity.

One of Swift’s key features is support for Codable, which makes it easy to convert JSON data into Swift objects and vice versa. With strong type safety, optionals, and automatic memory management, Swift simplifies working with structured data like JSON in mobile app development.

How to Use the JSON to Swift Converter

• Paste Your JSON: In the Input box at the top, enter or paste your JSON data.
• Auto Update is Enabled by Default: As you type or modify the JSON, the Swift code will be generated automatically in real-time. You can uncheck Auto Update if you prefer to convert manually.
• Click "JSON to Swift" (If Needed): If you have disabled Auto Update, click the JSON to Swift button to trigger the conversion manually.
• Check the Output: The converted Swift code will appear in the Output section below. It will follow Swift’s syntax and typically use Codable structs.
• Copy and Use in Your Project: Use the copy icon to quickly copy the generated Swift code and paste it into your Xcode project.

Use Cases of the JSON to Swift Struct Tool

• iOS App Development with APIs: When working with APIs that return JSON, developers often need to convert that data into Swift models. This tool helps generate ready-to-use Swift structs or classes from JSON instantly, saving time and effort.
• Generating Codable Models: Swift’s Codable protocol makes it easy to parse JSON, but writing the models manually can be tedious. This tool automatically creates Codable-compliant code based on your JSON input.
• Fast Prototyping and Mock Data Creation: Building a quick prototype or testing a feature with mock data becomes easier when you can paste sample JSON and get usable Swift models in seconds.
• Smoother Backend-to-Frontend Collaboration: When backend developers share JSON responses, frontend iOS developers can quickly convert them into Swift types using this tool. This speeds up development and reduces confusion.
• Learning Swift JSON Mapping: New iOS developers can better understand how JSON translates into Swift by using this tool. It offers a hands-on way to learn Swift model creation and type mapping.
• Using JSON from Swagger or Postman: If you're working with API response samples from tools like Swagger or Postman, this tool helps turn that raw JSON into Swift code without writing everything manually.
• Refactoring Hardcoded Dictionaries: If your code includes hardcoded JSON-like dictionaries, you can convert that structure into proper Swift models for better type safety and maintainability.

Frequently Asked Questions (FAQs)

Does the tool support converting large JSON files?

Yes, the tool can handle large JSON inputs, but extremely complex or deeply nested structures may affect performance depending on your browser.

Will it detect optional properties automatically?

Yes, the tool tries to infer optional properties based on missing or null values in the JSON. However, you should always review the output to ensure accuracy.

Is the generated Swift code production-ready?

The output is clean and well-formatted, but you should review and refactor it to match your project’s naming conventions, architecture, and error handling needs.

Is my JSON data stored or sent to a server?

No, your JSON input is processed entirely in your browser. The tool does not store, log, or transmit any data externally.