JSON to TypeScript Generator
Paste example JSON or an API response and generate readable TypeScript without uploading data.
0 bytes
TypeScript appears here. Everything runs in your browser.
Nested API responses
Objects and arrays are inferred recursively, including arrays of nested objects and repeated response items.
Conservative ambiguous types
Mixed primitive arrays become unions, empty arrays become unknown[], and null-only values stay null.
Safe property names
Invalid TypeScript identifiers are emitted as quoted keys, so API fields with spaces or hyphens still compile.
Related developer tools
JSON to TypeScript Generator
Infer TypeScript interfaces or type aliases from sample JSON values.
- Input
- Valid sample JSON plus root-name and output-style options.
- Output
- Copyable TypeScript type declarations.
- Real limitations
- Inference describes the sample, not every future payload; nulls, empty arrays, optional fields, unions, dates, and identifiers need developer review.
- Privacy and data handling
- valid sample JSON plus root-name and output-style options is processed in this browser tab. Convertr does not receive or store it; closing or reloading the page clears the working state unless the tool explicitly offers a local download.
How to use this tool
- Provide valid sample JSON plus root-name and output-style options in the tool controls.
- Choose the settings that affect copyable TypeScript type declarations, then run the tool.
- Review copyable TypeScript type declarations before copying or downloading it.
Common failure modes
Invalid JSON, a non-representative sample, or keys that require quoted properties can produce types that need adjustment.
Useful example
Paste a user object with id, name, and roles to generate a User interface with a string array.