JSON Formatter & Model Generator

Whether you copy a minified, single-line JSON payload from an API response or dump a massive log file into the editor, our tool instantly adds clean line breaks and perfect indentation. It serves as a highly efficient JSON unminify tool, allowing you to instantly restore readability to any compressed dataset.

You can easily customize the indentation style (e.g., 2 spaces, 4 spaces, or tabs) to match your team's coding conventions or personal preference. Even when handling massive JSON objects with thousands of lines, the clear tree structure ensures your data remains readable and easy to navigate.

Alongside formatting, our tool features a built-in, real-time JSON Validator that checks your code syntax on the fly.

A tiny JSON syntax error can break an entire system, yet these issues are notoriously easy to overlook. Common culprits behind broken JSON include:

• Trailing commas (which are strictly invalid according to standard JSON specifications)
• Single quotes instead of double quotes around keys or strings
• Missing or misplaced closing braces or brackets []
• Included comments (standard JSON does not support comments)

Our live JSON inspector automatically catches these syntax blunders, highlighting the exact line and explaining the cause of the error. This saves you from wasting time hunting down missing commas and keeps your development pipeline moving smoothly.

What truly sets Web Dev Toolkit apart from standard formatters is its ability to instantly convert JSON to Swift Codable and JSON to Kotlin data class models.

When building iOS or Android apps, developers frequently have to manually map API JSON responses to native data models. For iOS engineers, this means writing a struct that conforms to the Codable protocol. For Android engineers, it requires defining a Kotlin data class for serialization. When an API has dozens of fields, writing these structures by hand is tedious, repetitive, and highly prone to typos or optional-type mismatches.

Our tool dynamically analyzes the keys and inferred data types (String, Int, Bool, Array, or Nested Object) of your pasted JSON and generates production-ready boilerplate code instantly.

struct Root: Codable {
    let user: User
}

struct User: Codable {
    let id: Int
    let name: String
    let roles: [String]
    let profile: Profile
}

struct Profile: Codable {
    let age: Int
    let email: String
}

data class Root(
    val user: User
)

data class User(
    val id: Int,
    val name: String,
    val roles: List<String>,
    val profile: Profile
)

data class Profile(
    val age: Int,
    val email: String
)

Say goodbye to manually mapping data structures line by line. Whenever an API contract changes, simply paste the updated JSON payload, generate your new Swift or Kotlin models with a single click, and copy them right into your codebase.