Does it infer formats?

Yes — dates, date-times, emails, URIs and UUIDs are detected from string values.

How are arrays handled?

Item schemas are merged across all elements so mixed arrays produce a union-friendly schema.

Can I get TypeScript types?

Yes, switch the output format to TypeScript for ready-to-paste interfaces.

Is my data uploaded to a server?

No. This tool runs entirely in your browser using standard web APIs, so your input never leaves your device and nothing is logged or stored on our servers.

Does it work offline and on mobile?

Yes. Once the page has loaded it keeps working without a network connection, and the layout is responsive so it stays usable on phones and tablets.

API Response Schema Generator

Turn a JSON API response into OpenAPI, JSON Schema or TypeScript.

Support

Works Offline

Privacy First

No Login

No API

Output

Schema name

Status code

Infer formats

Include examples

Require all fields

Nullable for null

Example JSON response

Paste a real response body

Generated schema

responses:
  200:
    description: Successful response
    content:
      application/json:
        schema:
          $ref: "#/components/schemas/OrderResponse"
components:
  schemas:
    OrderResponse:
      type: object
      properties:
        id:
          type: string
          example: ord_1024
        total:
          type: number
          format: double
          example: 42.5
        currency:
          type: string
          example: USD
        createdAt:
          type: string
          format: "date-time"
          example: "2026-04-18T09:30:00Z"
        customer:
          type: object
          properties:
            id:
              type: integer
              format: int64
              example: 7
            email:
              type: string
              format: email
              example: ada@example.com
            vip:
              type: boolean
              example: true
          required:
            - id
            - email
            - vip
        items:
          type: array
          items:
            type: object
            properties:
              sku:
                type: string
                example: "TS-01"
              qty:
                type: integer
                format: int64
                example: 2
              price:
                type: number
                format: double
                example: 12.5
            required:
              - sku
              - qty
              - price
        coupon:
          type: string
          nullable: true
      required:
        - id
        - total
        - currency
        - createdAt
        - customer
        - items

About the API Response Schema Generator

Paste a sample API response and instantly get an OpenAPI 3 schema, a JSON Schema draft document or TypeScript interfaces — with nullable detection, array item merging, format inference for dates, emails and UUIDs, and optional example values.

Examples

User payload

{"id":1,"email":"a@b.com"}

Output

type: object · properties: id (integer), email (string, format: email)

Keyboard shortcuts

Copy the main outputCtrl / ⌘ + Shift + C
Download the resultCtrl / ⌘ + S
Share this toolCtrl / ⌘ + Shift + S
Reset the inputsAlt + R
Open the tool search paletteCtrl / ⌘ + K

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Frequently asked questions

Version 1.0.0 · Updated 2026-08-20 · Runs entirely in your browser