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 in your browser // nothing is uploaded

Loading tool

How it works

  1. 01

    Paste a JSON object or array.

  2. 02

    Review the generated TypeScript interfaces.

  3. 03

    Copy the output into your project.

Details

Formats
JSON
Runs
In your browser
Files uploaded
No
Cost per run
Free
Sign-in
Not required
Works offline
Yes, once loaded

Last updated 2026-08-03

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.

Related tools