JSON to TypeScript interface generator

What is JSON to TypeScript?

A JSON to TypeScript converter infers interfaces from a JSON example so API data can be typed in TypeScript projects.

Main use case: Generate TypeScript types from API responses, example payloads, fixtures or configuration objects.

Common use cases

API clients

Create interfaces from sample responses.

Frontend typing

Improve autocomplete and type safety.

Documentation

Show expected object shapes in technical docs.

How to use the tool

1. Paste a representative JSON example.
2. Set the root interface name.
3. Choose readonly if needed.
4. Copy the generated TypeScript.

Best practices

• Use realistic test values when validating forms, exports or API payloads.
• Keep real customer, banking and production secrets out of public tools.
• Check the output format before copying it into a production workflow.
• Document whether a value is generated, validated, converted or only estimated.

Common mistakes

Confusing valid format with real-world validity

A generated or locally validated value can match a format without proving that it exists in an official system.

Using real production data

Public utilities are best for test data, demos, fixtures, QA and quick checks, not for confidential values.