JSON Schema to TypeScript

How to use this developer tool

1. Paste json schema or load a local file.
2. Review any available processing options.
3. Select Generate TypeScript or press Ctrl/Cmd + Enter.
4. Check the summary and diagnostics, then copy or download the result.

What this developer tool does

Convert a practical subset of JSON Schema into readable TypeScript declarations in the browser. Required arrays control optional property markers, enums become literal unions, nullable type arrays are preserved, and nested objects are emitted inline. The generator also reports keywords it cannot represent exactly, so the output can be reviewed before it enters a codebase.

Nothing is uploaded by the core tool. Closing or refreshing the tab clears the current input.

Example

Input

{
  "$id": "User",
  "type": "object",
  "required": [
    "id",
    "role"
  ],
  "properties": {
    "id": {
      "type": "integer"
    },
    "name": {
      "type": [
        "string",
        "null"
      ]
    },
    "role": {
      "enum": [
        "admin",
        "member"
      ]
    },
    "settings": {
      "type": "object",
      "additionalProperties": {
        "type": "boolean"
      }
    }
  }
}

Result

export interface User {
  id: number;
  name?: string | null;
}

Use cases

• Review API payloads and fixtures before committing them.
• Diagnose generated JSON during development or testing.
• Prepare documentation, migrations, and typed interfaces.

Tips for reliable output

• Keep a copy of the original input before applying structural changes.
• Run invalid and edge-case samples as well as the happy path.
• Review warnings instead of treating generated output as a final contract.
• Use version control when replacing schemas or fixtures.
• Test downstream consumers after changing keys or required fields.

Processing details

JSON Schema to TypeScript runs with standard browser JavaScript and uses JSON syntax as defined by JSON.parse except where raw-source inspection is required.

Application-specific validation rules and remote references are not inferred. Very large documents are limited by the memory available to the browser tab.