JSON to TypeScript Types input is rejected
The source data may be incomplete, malformed, or different from the format this tool expects.
Check the input hint, try a small sample first, and correct the source file before running the full job.
Use this tool
Prepare the input and run the tool
Paste a JSON object or array sample. Result: Copy generated TypeScript interfaces with nested type definitions.
Ready. Paste JSON and generate types.
TypeScript interfaces appear here.
Data handling: Files and pasted data are processed in this browser session.
Tool guide
How to use JSON to TypeScript Types
Use JSON to TS when you need to check, convert, or prepare a file before using it in another app. Review the result before downloading or copying it.
What this tool does
Turn a JSON sample into TypeScript interfaces so developers can quickly type API responses, config files, and mock data.
- Input
- Paste a JSON object or array sample
- Output
- Copy generated TypeScript interfaces with nested type definitions
Tool advantages
- Runs in this page; the file or pasted data is not sent to a new app.
- Keeps the preview, report, and download in the same screen.
- Gives you a report you can use as a cleanup list.
Step-by-step usage guide
- 1Paste a representative JSON object or array.
- 2Choose a root interface name.
- 3Generate and copy TypeScript interfaces for your project.
Common errors and fixes
JSON to TypeScript Types result looks incomplete
The preview can only use the rows, files, or fields provided in the current browser session.
Confirm that the full source was pasted or selected, then rerun the tool and review the output before downloading.
JSON to TypeScript Types output needs extra cleanup
Some destination systems have rules that are stricter than a browser-local utility can infer.
Use the report as a cleanup checklist and verify the final file in the app where it will be imported or shared.
When to use JSON to TypeScript Types
- You are checking files before an upload, import, share, or delivery.
- You want to confirm the result before sending it to another system.
- You need a copied result, downloaded file, or report that can be reviewed outside the page.
FAQ
Can one JSON sample guarantee perfect production types?
No. It infers types from the sample you paste. Review optional fields, unions, and edge cases before committing the result.
Does it support arrays?
Yes. Arrays are inferred from their item values and nested object arrays generate additional interfaces.