OpenAPI/Swagger Validator

Validate your OpenAPI 3.0 or Swagger 2.0 specifications in JSON or YAML format.

Paste OpenAPI/Swagger Specification: Supports both JSON and YAML formats Validate Specification Reset

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How to Use the OpenAPI Validator

This tool validates your OpenAPI/Swagger specifications to ensure they follow the correct schema and best practices.

Step-by-Step Instructions:

1. Get your spec: Copy your OpenAPI or Swagger specification
2. Paste it: In the text area above (JSON or YAML format)
3. Validate: Click "Validate Specification"
4. Review results: Check for errors, warnings, and statistics
5. Fix issues: Address any validation errors found
6. Re-validate: Validate again after making changes

Example OpenAPI 3.0 Spec (YAML):

openapi: 3.0.0
info:
  title: User API
  version: 1.0.0
  description: API for managing users
paths:
  /users:
    get:
      summary: List all users
      responses:
        '200':
          description: Success
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/User'
  /users/{userId}:
    get:
      summary: Get user by ID
      parameters:
        - name: userId
          in: path
          required: true
          schema:
            type: integer
      responses:
        '200':
          description: Success
        '404':
          description: User not found
components:
  schemas:
    User:
      type: object
      properties:
        id:
          type: integer
        name:
          type: string
        email:
          type: string

What Gets Validated:

• Required fields: openapi/swagger version, info, paths
• Info section: title, version, description
• Path format: Paths should start with '/'
• HTTP methods: Valid HTTP verbs
• Responses: Each operation should have responses
• Components/Definitions: Schema definitions

Common Validation Errors:

• Missing required fields (openapi, info, paths)
• Invalid version format
• Paths not starting with '/'
• Operations without responses
• Invalid JSON or YAML syntax

OpenAPI vs Swagger:

• Swagger 2.0: Older specification, uses 'swagger: 2.0'
• OpenAPI 3.0+: Newer specification, uses 'openapi: 3.0.0' or higher
• Key differences: OpenAPI 3.0 has better support for components, callbacks, and links

Benefits of Valid Specs:

• Auto-generate API documentation (Swagger UI, ReDoc)
• Generate client SDKs in multiple languages
• Enable API testing and validation tools
• Improve API discoverability and usability
• Enforce API design standards across teams

Related Tools:

• API Response Mocker - Create mock responses
• JSON Beautifier - Format JSON specs
• YAML Formatter - Format YAML specs
• HTTP Status Codes - Status code reference
• JSON Schema Generator - Generate schemas