OpenAPI Viewer

What is OpenAPI?

OpenAPI (formerly known as Swagger) is the industry-standard specification for describing RESTful APIs. It provides a machine-readable format that documents your API's endpoints, parameters, request/response schemas, authentication methods, and more. This tool parses OpenAPI 3.x specifications and displays them as interactive, human-readable documentation.

How to Use

1. Paste your OpenAPI specification (JSON or YAML format) into the text area
2. Or click "Upload File" to load a .json, .yaml, or .yml file
3. Click "Parse Specification" to process and display the documentation
4. Browse endpoints organized by tags
5. Expand operations to see parameters, request bodies, and responses

Supported Formats

OpenAPI 3.0 (JSON)

{
  "openapi": "3.0.0",
  "info": {
    "title": "My API",
    "version": "1.0.0"
  },
  "paths": {
    "/users": {
      "get": {
        "summary": "Get all users",
        "responses": {
          "200": {
            "description": "Success"
          }
        }
      }
    }
  }
}

OpenAPI 3.1 (YAML)

openapi: 3.1.0
info:
  title: My API
  version: 1.0.0
paths:
  /users:
    get:
      summary: Get all users
      responses:
        '200':
          description: Success

Features

• Tag-Based Organization: Endpoints are automatically grouped by their tags for easy navigation
• Interactive Documentation: Click to expand operations and see detailed information
• Schema Visualization: Request and response schemas are displayed with type information
• Web Worker Processing: Large specifications (>50KB) are parsed in a background thread to keep the UI responsive
• Dual Format Support: Works with both JSON and YAML OpenAPI specifications
• Version Support: Compatible with OpenAPI 3.0.x and 3.1.x

Common Use Cases

• Preview OpenAPI specifications before publishing
• Explore third-party APIs documented with OpenAPI
• Validate OpenAPI spec structure and completeness
• Share API documentation with team members
• Convert between JSON and YAML formats
• Review API design and endpoint organization

Understanding OpenAPI Components

• Info: API metadata including title, version, and description
• Servers: Base URLs where the API is hosted
• Paths: Available endpoints and their operations (GET, POST, etc.)
• Components: Reusable schemas, parameters, and security definitions
• Tags: Logical groupings for organizing endpoints
• Security: Authentication and authorization schemes

Performance Optimization

For large OpenAPI specifications (over 50KB), this tool automatically uses a Web Worker to parse the specification in a background thread. This keeps the user interface responsive even when processing complex APIs with hundreds of endpoints. You'll see a loading indicator while the specification is being parsed.

Privacy Notice

All specification parsing and viewing happens entirely in your browser. Your OpenAPI specifications, which may contain internal API details, authentication schemes, or proprietary data models, never leave your device. This ensures complete privacy when working with confidential or pre-release API specifications.