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JSON to TypeScript

This free tool allows you to quickly convert JSON data into TypeScript interfaces for APIs, frontend apps, or JS to TS migration.

What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based data format used for storing and exchanging data. It is easy to read and write for humans, and easy to parse and generate for machines. Although derived from JavaScript, JSON is language-independent and widely supported across many programming environments.

Key Characteristics:

Structured as key-value pairs
Uses curly braces { } for objects and square brackets [ ] for arrays
Supports basic data types: string, number, boolean, array, object, and null
Commonly used in web applications, APIs, and configuration files

What is TypeScript?

TypeScript is a strongly typed, open-source programming language developed and maintained by Microsoft. It is a strict syntactical superset of JavaScript, meaning all valid JavaScript code is also valid TypeScript code, with the addition of static typing and other advanced features.

Key Features

Static Type Checking: Enables developers to identify and fix type-related errors during development, before code is executed.
Type Annotations: Allows explicit declaration of variable types, function parameters, and return values.
Interfaces and Type Aliases: Provides tools to define the structure of complex data and APIs.
Modern JavaScript Support: Includes support for the latest ECMAScript features.
Compilation to JavaScript: TypeScript is transpiled into standard JavaScript, ensuring compatibility across all JavaScript environments.

How to Use the JSON to TypeScript Converter Online

Enter JSON Input: Paste your JSON data into the input box labeled "Enter JSON here".
Auto Conversion: Auto Update is enabled by default. Your JSON will be converted to a TypeScript interface instantly as you type.
Manual Conversion (Optional): If you turn off Auto Update, click the "JSON to Typescript" button to convert manually.
View the Output: The converted TypeScript interface will appear in the output section below.
Use Toolbar Icons:
- Copy the input or output.
- Clear the fields
- Format or reset your JSON as needed

What is JSON to TypeScript Conversion Online?

JSON to TypeScript conversion is the process of transforming JSON objects into corresponding TypeScript interfaces. This helps developers take advantage of TypeScript’s static type-checking by defining the structure of data in a clear and maintainable way.

If you're switching from JavaScript to TypeScript or working on a new TS project, this JavaScript to TypeScript converter online makes the transition seamless.

Can I convert deeply nested JSON structures?

Yes, the tool supports deeply nested objects and arrays. It automatically generates properly structured TypeScript interfaces for complex JSON data.

What happens if my JSON is invalid or has errors?

If your JSON input is malformed or invalid, the tool will not generate TypeScript output. Make sure your JSON is properly formatted before conversion. You can use the format or reset option to clean it up.

Is this tool safe to use with sensitive data?

Yes. This tool runs entirely in your browser and does not send or store your data anywhere. It is 100% client-side and secure for handling sensitive or private JSON.

Can I use this tool offline?

Currently, the tool requires an internet connection to access and load. However, once opened, most conversions are processed in-browser without server dependency.

Does it support JSON arrays at the root level?

Yes. If your JSON starts with an array, the tool will still generate the appropriate TypeScript type using array notation and infer the item type automatically.

Which browsers are supported?

The tool works smoothly on all modern browsers, including Chrome, Firefox, Edge, Safari, and Brave. JavaScript must be enabled for full functionality.