ToolCoveToolCove
HomeToolsAboutBlog
HomeToolsJSON to TypeScript

JSON to TypeScript

Generate TypeScript interfaces and types from JSON data. Paste JSON and get accurate type definitions instantly.

Generate TS interfacesHandle nested objectsArray type inferenceOptional field detectionCopy generated typesClient-side only
TypeScript interfaces will appear here...

How to Generate TypeScript from JSON

  1. 1Optionally set a custom root interface name (default: "Root")
  2. 2Paste your JSON data into the left input area
  3. 3Click "Generate TypeScript" to create type definitions
  4. 4View the generated interfaces in the right panel
  5. 5Nested objects automatically get their own interfaces
  6. 6Click the copy button to copy the TypeScript code

Frequently Asked Questions

How does JSON to TypeScript conversion work?

The tool analyzes your JSON structure and infers TypeScript types. Objects become interfaces, arrays get typed based on their contents, and primitives map to string, number, or boolean. Nested objects generate separate named interfaces.

Does it handle arrays with mixed types?

Yes. If an array contains elements of different types (e.g., strings and numbers), the tool generates a union type like (string | number)[]. For arrays of objects, it merges all objects to capture every field.

Can I customize the interface names?

You can set the root interface name via the input field. Nested interfaces are named based on their JSON key (e.g., the "address" key generates an "Address" interface).

Does it generate types or interfaces?

It generates export interface declarations for objects and export type aliases for arrays and primitives. This follows TypeScript best practices for most use cases.

Is my JSON data private?

Yes. Type generation runs entirely in your browser. No data is uploaded or processed on any server.

Related Tools

JSON Formatter & Validator

Format, validate, and beautify JSON data with syntax highlighting. Perfect for debugging API responses and configuration files.

Try this tool

JSON to CSV Converter

Convert JSON arrays and objects to CSV format instantly. Handles nested data, auto-detects headers, and produces clean comma-separated output.

Try this tool

JSON Validator

Validate JSON syntax instantly. Detect errors, find missing brackets, and check data integrity — all in your browser.

Try this tool

Need More Developer Tools?

Explore our complete collection of free online developer utilities

View All Tools