JSON to TypeScript

Convert JSON objects into TypeScript interfaces with automatic type inference, nested object support, and array detection.

🔷 JSON to TypeScript

Convert JSON objects into TypeScript interfaces instantly

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⚙ī¸ Options
ℹī¸ Nested objects and arrays are automatically converted into separate interfaces. Array item types are inferred from their contents.
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Paste JSON above and click "Convert" to generate TypeScript interfaces

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What is a JSON to TypeScript Converter?

A JSON to TypeScript converter is a tool that takes a JSON object or array and automatically generates TypeScript interface definitions that match the data structure. TypeScript interfaces provide type safety and autocompletion in your IDE, but writing them manually from API responses or JSON data is tedious and error-prone.

CodeHelper's JSON to TypeScript Converter handles nested objects (creating separate interfaces), arrays (with item type inference), union types for mixed arrays, and null values: all in a single click.

Key Features

  • Automatic Type Inference: Detects string, number, boolean, null, object, and array types from your JSON data.
  • Nested Interfaces: Nested objects are extracted into their own named interfaces for clean, reusable code.
  • Array Detection: Arrays are typed based on their contents, including union types for mixed arrays.
  • Export Toggle: Add the export keyword to all generated interfaces.
  • Optional Properties: Mark all properties as optional with the ? modifier.

How to use the JSON to TypeScript Converter

  1. Paste your JSON data into the input area.
  2. Set the root interface name (defaults to "Root").
  3. Toggle export and optional properties as needed.
  4. Click Convert to generate TypeScript interfaces.
  5. Copy the output or download it as a .ts file.

Whether you are consuming REST APIs, working with configuration files, or bootstrapping a new TypeScript project, this free tool generates accurate type definitions from any JSON structure in seconds.