utiloralab.
Developer tools / Free online tool

JSON to TypeScript

Generate a TypeScript type from a JSON sample. Start with real data, skip the boilerplate.

Runs in your browser
0 characters
OUTPUT
Your result will appear here

A little input. A useful output.

Ctrl + Enter to run

Your input stays on your device. No uploads. No account. Just your result.

How to use JSON to TypeScript

  1. 01

    Paste a representative JSON sample.

  2. 02

    Generate a type.

  3. 03

    Review optional fields and domain constraints in your editor.

A quick example

Try a simple example

INPUT
{"name":"Ada","active":true}
OUTPUT
export type Root = {
  "name": string;
  "active": boolean;
};

About JSON to TypeScript

Type inference examines the supplied sample to produce a Root type. Mixed arrays become unions, empty arrays use unknown[], and nested objects remain inline.

When it comes in handy

  • Bootstrap API response types.
  • Document example payloads.

Why use it here?

  • Runs locally in your browser.
  • No account needed; copy or download your result.

A few things to keep in mind

  • One sample cannot reveal optional fields.
  • Inference stops at 20 nesting levels.

Good questions. Simple answers.

Will this replace a schema?

No. Review the generated type against all possible responses before using it in production.

Is my input uploaded?

No. This tool processes your input in your browser. Your input and output are not included in analytics.

A good next step

Useful tools that go well together.

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