OpenAPI Spec Generator
Online OpenAPI spec generator with visual API info and endpoint editing, generating OpenAPI 3.0 documents in real time and exporting JSON or YAML.
API Info
API Endpoints
Click "Add Endpoint" to create your first API endpoint
Quick Templates
OpenAPI Spec
Fill API fields and endpoints, then the spec updates automatically
Structure Stats
Endpoints
0
Paths
0
Output Size
0 B
Guide
OpenAPI Spec Generator helps teams draft OpenAPI 3.0 files quickly with visual endpoint editing and real-time output, reducing repetitive manual spec writing.
Key Features
- Edit API title, version, description, server URL, and base path visually.
- Add, update, and remove endpoints with method, path, summary, and description.
- Switch between JSON and YAML output formats instantly.
- Use quick templates to bootstrap CRUD, RESTful, and auth API specs.
How To Use
- Fill API metadata and confirm server URL plus base path.
- Add endpoints and complete method, path, and description fields.
- Switch JSON or YAML format and verify generated output.
- Copy or download the spec for design review and integration handoff.
OpenAPI Structure Notes
Info
Stores API metadata such as title, version, and description for documentation and release tracking.
Paths
Defines endpoint URLs and HTTP operations, where each path can include multiple methods.
Components
Holds reusable schemas, parameters, and security definitions for scalable API governance.
Use Cases
- Draft review-ready OpenAPI specs during backend API design
- Align frontend and backend route contracts before integration
- Prepare API test plans and regression checklists for QA
- Deliver versioned API docs for cross-team collaboration
FAQ
- Does it require network calls: no, generation runs locally in your browser.
- Which formats are supported: JSON and YAML OpenAPI text output.
- Will empty paths be kept: no, endpoints without path are skipped in paths.
- How is download file name generated: it uses the API title by default.
Privacy
This tool does not upload your API data. All parsing and generation run locally in the browser.