What Is OpenAPI / Swagger?
OpenAPI (formerly Swagger) is the industry-standard specification for describing RESTful APIs. An OpenAPI document defines your API endpoints, request and response formats, authentication methods, and data schemas in a machine-readable YAML or JSON file. It is widely used for API documentation, client SDK generation, and automated testing.
How to Use This OpenAPI Viewer
- 1Paste your OpenAPI 3.x specification in YAML or JSON format into the text area.
- 2The tool automatically parses and displays API info, endpoints, and schemas.
- 3Click any endpoint to expand details including parameters, request body, and response codes.
- 4Use the filter bar to search endpoints by path, method, summary, or tag.
- 5Click a schema name to view its properties and required fields.
Common Use Cases
Quick API Documentation Review
Visualize an API spec without running a full Swagger UI server.
Schema Validation
Check that your data models and endpoint definitions are correct before generating client code.
API Design Collaboration
Share and review API designs by pasting specs during code reviews or planning meetings.
Frequently asked questions
Does this support OpenAPI 2.0 (Swagger)?
This viewer is optimized for OpenAPI 3.x. Swagger 2.0 specs may partially work but some fields like consumes/produces are not rendered.
Is my API spec sent to any server?
No. All parsing and rendering happens entirely in your browser. No data leaves your machine.
Can I import from a URL?
Currently you need to paste the spec content directly. Copy the raw YAML/JSON from your file or URL and paste it here.