JSON to TypeScript
Turn a JSON object into TypeScript interfaces. Nested objects and arrays are inferred automatically.
Paste a JSON object or API response and get back ready-to-use TypeScript interfaces, with nested objects broken out into their own named types and array element types inferred from their contents. Saves the tedium of hand-typing interfaces for a third-party API response or a large config object. Generation runs entirely in your browser - paste, review, and copy the interfaces straight into your codebase.
Runs on your device. This tool processes your file inside this browser tab. Nothing is uploaded, so it also works offline once the page has loaded, and closing the tab discards the file from memory.
Loading tool
How it works
- 01
Paste a JSON object or array.
- 02
Review the generated TypeScript interfaces.
- 03
Copy the output into your project.
Details
- Category
- Developer & data
- Formats
- JSON
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-12
Common questions
Does it handle nested objects?
Yes - each nested object becomes its own named interface.
What about mixed-type arrays?
The type is inferred from the first element; mixed arrays may need manual adjustment.
Does it detect optional fields?
Fields present in the sample JSON are treated as required. Review and mark fields optional manually if your real API responses can omit them.
Is my JSON uploaded anywhere?
No - generation runs entirely in your browser.
Use this from your code
This tool is also a REST endpoint, so you can run it in a pipeline instead of by hand. It is free and needs no API key. See the API reference for every parameter.
curl -X POST https://fileoven.com/api/v1/tools/json-to-ts \
-H "Content-Type: application/json" \
-d '{"json":"{\"id\":1,\"name\":\"Ada\"}"}'