Draft an API response type
Generate nested TypeScript structures quickly from sample JSON.
JSON to TypeScript Converter
JSON to TypeScript Converter
Analyze a JSON object or array and generate nested TypeScript interfaces or type aliases.
Key features
- Infers nested TypeScript structures from JSON objects and arrays.
- Switches output between interface declarations and type aliases.
- Sanitizes an optional root name into a valid TypeScript identifier.
- Validates JSON syntax and the top-level data shape before conversion.
How to use
- Enter JSON whose root is an object or array.
- Optionally set a root name and enable type aliases.
- Copy the generated TypeScript declarations.
Examples
Type mock data
Paste an object array and create a reusable interface or type alias.
Privacy
JSON parsing and TypeScript type generation run in your browser.
Requirements
The top-level JSON must be an object or array, and generated types are inferred from the sample values.
Common questions
- Does it inspect multiple array items?
- It examines array element shapes to form a shared TypeScript type, but the result reflects only the supplied sample and cannot cover unseen API variants.
- Can I choose between interface and type?
- Yes. Switch the declaration style between interfaces and type aliases and set the root type name.
Related tools
- JSON Formatter and ValidatorFormat, minify, sort, and validate JSON with clear syntax error locations.
- JSON, YAML, and CSV ConverterConvert between JSON, YAML, and header-based CSV while seeing source-format syntax errors immediately.
- Case Converter for Developer Naming StylesConvert English text into camelCase, PascalCase, snake_case, and six other naming styles at once.
- HTML, CSS & JavaScript Code PlaygroundEdit HTML, CSS, and JavaScript, inspect a sandboxed iframe preview and console, then download a standalone HTML file.