JSON to TypeScript
Generate TypeScript types from JSON
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JSON to TypeScript
Generate TypeScript types from JSON
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About this tool
Drop in any JSON and get ready-to-use TypeScript interfaces with inferred nested and array types.
The JSON to TypeScript Interface converter automatically generates strongly-typed TypeScript interface definitions from any JSON structure. Instead of manually writing interface files for API responses, configuration objects, or database records, paste your JSON and get production-ready TypeScript code with proper nesting, optional markers, union types, and JSDoc-ready comments in seconds.
The converter intelligently infers types from actual values — strings become string, numbers become number, booleans become boolean, arrays derive their element type, and nested objects become sub-interfaces with proper naming. When a field has multiple types across array elements or is null, the tool generates accurate union types (string | number) or optional (?) modifiers, ensuring your generated types are correct on the first pass.
Whether you're scaffolding types for a new API integration, generating configuration schemas, or building a type-safe layer over an existing REST API, this tool eliminates hours of manual type definition work. All processing is client-side, so proprietary JSON payloads never leave your browser.
Key features
Everything you get with JSON to TypeScript — no premium upsell.
Automatic interface generation with proper nesting and naming conventions
Intelligent type inference: string, number, boolean, null, arrays, and unions
Optional (?) field markers for nullable or missing properties
Array element type detection with proper generic syntax
Configurable output: interfaces vs types, export keywords, naming style
Entirely client-side — no JSON data transmitted to external servers
How to use JSON to TypeScript
Follow the steps below to use the tool.
- 1
Paste JSON Data
Insert your JSON object, array, or API response into the input area.
- 2
Generate Interfaces
Click convert to produce TypeScript interface definitions with properly inferred types and nesting.
- 3
Configure Output
Toggle options like export keyword, interface vs type alias, and prefix/suffix for generated names.
- 4
Copy to Clipboard
One-click copy the generated TypeScript code to paste directly into your .ts files.
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Launch JSON to TypeScriptFrequently asked questions
Quick answers before you launch the tool.
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