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How do I convert JSON to TypeScript types?

Short answer

Paste a sample JSON payload into a browser-based JSON-to-TypeScript converter and it generates matching interface definitions you can drop straight into your code. The generation happens locally, so pasting a real API response, tokens, user data and all, does not send it anywhere.

From payload to interfaces in seconds

Hand-writing types for a large API response is tedious and error-prone. A generator walks the JSON, infers the type of each field, and emits nested interfaces with the right property names, turning ten minutes of transcription into a paste and a copy. It is the quickest way to get real type safety over an external API.

A sample is only a sample

The generated types describe the one payload you pasted, not the API contract. Fields that are sometimes null, optional properties that happened to be present, and unions the sample did not cover all need a human pass. Treat the output as a strong first draft: generate from a representative response, then mark the optional and nullable fields you know about.

Step by step

  1. Paste sample JSON. Paste a representative JSON response into the converter.
  2. Generate the types. The interfaces are generated locally in your browser.
  3. Refine and use. Copy the TypeScript into your project and adjust optional and nullable fields as needed.

Frequently asked questions

Is my payload uploaded?

No. Type generation runs entirely in your browser, so real API responses stay on your machine.

Will the types be perfect?

They will match the sample exactly, but a single sample cannot reveal optional or nullable fields, so review the output against the API docs.

Does it handle nested objects and arrays?

Yes. Nested structures become nested interfaces, and arrays are typed from their elements.

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