ZeroServer.tools

OpenAPI Validator

Validate OpenAPI 3.0 / 3.1 and Swagger 2.0 specs against the official schemas — YAML or JSON, entirely in your browser.

OpenAPI / Swagger YAML or JSON

openapi: "3.0.0"
info:
  title: Sample API
  version: "1.0.0"
  description: A sample API to demonstrate OpenAPI validation
paths:
  /users:
    get:
      summary: List users
      operationId: listUsers
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: "#/components/schemas/User"
  /users/{id}:
    get:
      summary: Get user by ID
      operationId: getUser
      parameters:
        - name: id
          in: path
          required: true
          schema:
            type: integer
      responses:
        "200":
          description: OK
          content:
            application/json:
              schema:
                $ref: "#/components/schemas/User"
        "404":
          description: Not found
components:
  schemas:
    User:
      type: object
      required:
        - id
        - name
      properties:
        id:
          type: integer
        name:
          type: string
        email:
          type: string

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OpenAPI Validator — check OpenAPI 3.0/3.1 and Swagger 2.0 specs against the official schemas

OpenAPI (formerly Swagger) is the industry standard for describing REST APIs. Unlike a hand-rolled field checker, this tool validates your document against the official OpenAPI meta-schemas — Swagger 2.0, OpenAPI 3.0, and OpenAPI 3.1 — using a real, spec-compliant JSON Schema engine (@cfworker/json-schema), so it enforces the full structure: the info object, paths and operation shapes, parameter and request-body objects, response content, and component definitions. It auto-detects the version from your openapi/swagger field, reports each problem as a JSON Pointer, resolves every internal $ref (both 3.x #/components/… and Swagger 2.0 #/definitions/…) to make sure it points at something real, and flags operations missing an operationId. Both YAML and JSON are accepted, and everything runs locally in your browser — no server, no eval.