JSON to TypeScript Interface

JSON to TypeScript Interface Generator

Paste a payload and get interfaces in seconds. All JSON processing runs locally in your browser, your data is never sent to any remote server.

JSON to TypeScript converter

Types update as you type. All JSON processing runs locally in your browser, your data is never sent to any remote server.

TypeScript output
// Generated locally in your browser. No data was sent to a server.

export enum Status {
  Complete = "complete",
  Draft = "draft",
}

export interface Profile {
  email: string;
  score: number;
}

export interface Project {
  title: string;
  status: Status;
}

export interface RootObject {
  id: number;
  name: string;
  active: boolean;
  role: string;
  profile: Profile;
  tags: string[];
  projects: Project[];
}

FAQ

How to convert nested JSON to TypeScript interface?

Paste nested JSON in the input panel. Nested objects become nested interfaces and arrays become typed lists you can copy.

Does this tool send my JSON data to server?

No. All JSON processing runs locally in your browser, your data is never sent to any remote server.

How to generate TypeScript interface from API JSON response?

Copy a JSON response from your network tab or fixture, paste it here, and generate. Set the root interface name to match the API resource.

Is this JSON to TS interface generator free?

Yes. It is free, with no signup and no usage cap.

What is the difference between TypeScript interface and type alias?

This tool outputs interfaces by default. Interfaces can be extended, while type aliases cannot. If you need type aliases, you can easily convert the generated interface manually.

Can I convert top-level JSON array to TypeScript interface?

Yes. Simply paste a JSON array as your input, and the tool will automatically generate matching TypeScript interfaces for array items.

Can it handle JSON with null and optional properties?

Yes. The tool detects null values and missing fields from your JSON sample and marks those properties as optional or nullable in the output interfaces.

Convert nested JSON and JSON arrays to TypeScript interfaces online

API samples are rarely flat. This json to typescript interface generator walks nested objects, nested arrays, and mixed optional fields, then emits clean interfaces you can paste into a project. Drop in a root JSON array of records and it still infers a reusable item type instead of failing on the first bracket.

Optional keys, null values, and repeated object shapes are merged so the output stays readable. Enum-like string fields are called out when the sample is consistent. You can set the root interface name before you copy the result.

No data upload: conversion stays in your browser

All JSON processing runs locally in your browser, your data is never sent to any remote server. There is no conversion API, no paste log, and no account database. That matters when the payload includes tokens, internal URLs, or unfinished schemas you would not send to a hosted playground.

Format, generate, and copy all happen on this page. Closing the tab is enough to drop the sample. The same no data upload promise is documented on the Privacy Policy page.

Free to generate TypeScript from JSON online, no signup

Use this page whenever you need a json to ts interface from a fixture, a network tab dump, or a mocked response. It is free, no signup, and there is no rate limit on how often you paste a new sample.

Keep Generate as a manual rerun if you want one, but valid JSON also converts automatically as you type. Nothing here requires an email address or a paid plan.