π Input OpenAPI Specification
Paste your OpenAPI/Swagger specification (JSON or YAML), or drag and drop a file.
π Drag and drop JSON/YAML file here
Or click the button below to select a file
π OpenAPI Specification Guide
What is OpenAPI Specification
OpenAPI Specification (OAS, formerly Swagger Specification) is an open standard under the Linux Foundation for describing RESTful API interfaces. It uses JSON or YAML format to define complete information about API endpoint paths, HTTP methods, request parameters, request bodies, response formats, and security authentication, making API documentation machine-readable and automatically processable.
OpenAPI 3.x vs Swagger 2.0
- Version identifier: OpenAPI 3.x uses
openapi: "3.x.x", Swagger 2.0 usesswagger: "2.0" - Request body: OpenAPI 3.x uses
requestBody, Swagger 2.0 usesparameterswithin: body - Component reuse: OpenAPI 3.x uses
components, Swagger 2.0 usesdefinitions - Security definitions: OpenAPI 3.x uses
components/securitySchemes, Swagger 2.0 usessecurityDefinitions - Composition schemas: OpenAPI 3.x supports
oneOf/anyOf/allOfcomposition - Callbacks and links: OpenAPI 3.x adds
callbacksandlinkssupport
Core Structure
- openapi/swagger: Specification version number
- info: API metadata (title, description, version, etc.)
- servers/host+basePath: API server address
- paths: API endpoint paths and method definitions
- components/definitions: Reusable schema components
- security: Global security requirements
- tags: Endpoint grouping tags
When to use OpenAPI Spec Viewer
- API documentation generation: Auto-generate interactive API documentation from specifications
- Code generation: Auto-generate client SDKs and server stub code
- API testing: Auto-generate test cases based on specifications
- API governance: Centrally manage microservice API interface definitions
- Team collaboration: Design-First development workflow
π FAQ
What is OpenAPI Specification?
OpenAPI Specification (OAS, formerly Swagger Specification) is a standardized format for describing RESTful APIs. It uses JSON or YAML syntax to define API endpoints, request parameters, response formats, authentication methods, and more, making API documentation machine-readable and enabling automatic client code generation.
What is the difference between OpenAPI 3.x and Swagger 2.0?
OpenAPI 3.x is the successor to Swagger 2.0. Key differences: 1) Uses openapi field instead of swagger; 2) Supports oneOf/anyOf/allOf composition schemas; 3) Improved security definitions with components/securitySchemes; 4) Supports callbacks and links; 5) Uses requestBody instead of body parameters.
How to validate an OpenAPI specification file?
This tool automatically detects and parses OpenAPI/Swagger specification files, checks JSON/YAML syntax correctness, verifies required fields (openapi/swagger, info, paths), and highlights missing or malformed sections.
What formats of OpenAPI files are supported?
Both JSON and YAML formats are supported. You can paste content directly, drag and drop files, or import via URL. Supports OpenAPI 3.0.x, 3.1.x, and Swagger 2.0 versions.
Is my data uploaded to a server?
No. All OpenAPI specification parsing and visualization happens locally in your browser. Your API specification content is never sent to any server, ensuring your API design security.
How to view API endpoints with this tool?
Paste your OpenAPI specification content into the input area or drag and drop a file. The tool will automatically parse and display all API endpoints in a tree structure. Click any endpoint to view detailed request parameters, response formats, and example data.