Embed this tool on your site 
<iframe src="https://devtoolbox.dedyn.io/tools/json-to-typescript" width="100%" height="600" frameborder="0" title="JSON to TypeScript Converter"></iframe>

JSON to TypeScript Converter

Generate TypeScript interfaces or type aliases from JSON data. Handles nested objects, arrays, optional fields, and readonly properties. Everything runs in your browser — your data stays private.

 
TypeScript interfaces will appear here...

About JSON to TypeScript Conversion

TypeScript's type system brings safety and tooling support to JavaScript projects. When working with JSON data from APIs, configuration files, or databases, having accurate type definitions saves time and prevents bugs. This tool automates the process of writing those types by analyzing your JSON structure.

The converter inspects every value in your JSON, determines the correct TypeScript type, and creates clean, readable interfaces. Nested objects become separate named interfaces. Arrays are analyzed to determine element types, including union types when array elements have different shapes. When multiple objects in an array have different keys, fields unique to some objects are marked as optional.

Features

Related Tools

{ }

JSON Formatter

Format and validate JSON data
YML

JSON to YAML

Convert between JSON and YAML
JSON

JSON Validator

Validate JSON syntax

Frequently Asked Questions

How does JSON to TypeScript conversion work?▼
The converter analyzes the structure of your JSON data and generates corresponding TypeScript interfaces or type aliases. Each JSON object becomes an interface with typed properties. Nested objects create separate named interfaces, arrays are typed based on their element types, and primitive values (strings, numbers, booleans, null) map directly to TypeScript primitive types.
Should I use TypeScript interfaces or type aliases for JSON data?▼
Both interfaces and type aliases work well for representing JSON structures. Interfaces are generally preferred when you might extend or implement them later, and they provide better error messages. Type aliases are more flexible for union types and mapped types. For most JSON-to-TypeScript conversions, interfaces are the conventional choice, but either approach is valid.
Is my JSON data safe when using this converter?▼
Yes, completely. This JSON to TypeScript converter runs 100% in your browser using client-side JavaScript. Your JSON data never leaves your computer and nothing is sent to any server. You can verify this by checking the network tab in your browser's developer tools, or even use the tool offline once the page has loaded.
Keyboard Shortcuts
Ctrl+Enter Convert
Ctrl+Shift+C Copy output
Ctrl+L Clear