How it works
- Paste a representative JSON response.
- Choose the root interface name.
- Generate TypeScript and review optional fields manually.
API typing helper
JSON to TypeScript
Paste a JSON sample, choose a root type name and generate TypeScript interfaces that you can review and adapt for your project.
Result
Fill in the fields to see the result
The processed output appears here after you run the tool.
Generated output
Best input
Use a realistic JSON sample with nested objects and arrays so the inferred interfaces are closer to your API shape.
What is inferred
The tool infers primitive types, arrays and nested objects from actual values in the sample.
Manual review
Generated interfaces are a starting point. Review optional fields, nullability and business-specific naming.
Common use cases
- Create starter types for API responses.
- Document payloads during prototyping.
- Turn sample JSON into code you can refine.
Limitations
- The result depends on the example you paste.
- Optional fields and complex unions may need manual edits.
- Generated types should be reviewed before production use.
Frequently asked questions
Is the generated TypeScript production-ready?
It is a useful starting point, but you should review it before using it in production.
Does it work with arrays?
Yes. Arrays of objects generate item interfaces.
Is the JSON sent to a server?
No. Inference runs locally in the browser.
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