API Documentation Generator
Build API docs from endpoint definitions or import an OpenAPI spec — export Markdown, OpenAPI 3.0 JSON, or a Postman collection, with a live preview.
About this ToolHow it works, benefits & use casesTap to collapse
Build API documentation from a structured editor instead of hand-writing it. Fill in your API's title, base URL, version, and description, then add endpoints — each with an HTTP method, path, description, an authentication flag, and a list of parameters (name, type, required, description). A live preview regenerates on every keystroke and a stats bar shows endpoint, parameter, and authenticated-endpoint counts plus a per-method breakdown. Choose any of three output formats: Markdown reference docs, an OpenAPI 3.0 JSON spec, or a Postman collection — switching the format re-renders instantly. You can also work backwards: paste an existing OpenAPI / Swagger JSON spec into the importer and it populates the endpoint editor for you. Settings persist locally, and the output downloads with the right filename and MIME type for each format.
How to Use
- 1Enter the API info — title, base URL, version, and description — or click Load example to start from a sample.
- 2Pick an Output format: Markdown, OpenAPI 3.0 (JSON), or Postman Collection.
- 3Click Add endpoint, then set its method, path, description, and whether it requires authentication.
- 4Use Add parameter on each endpoint to define query/path parameters with name, type, required flag, and description.
- 5Watch the live preview and stats update as you type; press Generate documentation, then copy or download.
- 6To start from an existing spec, click Import OpenAPI, paste the JSON, and Import & populate endpoints.
Key Benefits
- Structured endpoint editor with methods, paths, auth flags, and typed parameters
- Three export formats from one definition: Markdown, OpenAPI 3.0 JSON, and Postman collection
- Live preview that re-renders on every edit and on format switch
- Stats bar with endpoint, parameter, authenticated, and per-method counts
- Import an existing OpenAPI / Swagger JSON spec to auto-populate the editor
- Per-format filename and MIME type so downloads are ready to use
- Configuration persists locally between sessions
Common Use Cases
- Drafting Markdown API reference docs for a README or docs site
- Producing an OpenAPI 3.0 spec to feed Swagger UI or code generators
- Exporting a Postman collection so teammates can try endpoints immediately
- Converting an existing OpenAPI spec into clean Markdown documentation
- Keeping endpoint definitions in one place and exporting whichever format a tool needs
API info
Endpoints
Endpoint 1
No parameters yet — click “Add parameter” to add one.
Add a title and at least one endpoint to preview.
API title is required.
Was this tool helpful?
Share Your Experience
Help others discover this tool!
Related tools
- Markdown to HTMLConvert Markdown to HTML
- Changelog GeneratorGenerate changelog from Git commit history
- Component Name GeneratorTurn a description into ranked, kind-aware component names with a file scaffold and a name validator (casing, collisions, clarity)
- Heroku Procfile GeneratorBuild a Heroku Procfile and matching app.json — process types, env vars, addons, dyno formation — plus a Procfile parser and audit
- Markdown TOC GeneratorGenerate table of contents for Markdown
- Package.json Scripts GeneratorGenerate common npm scripts for different project types and workflows
Three: a Markdown API reference, an OpenAPI 3.0 JSON specification, and a Postman collection. The same set of endpoints renders to whichever format you select, and switching formats re-renders the preview instantly with the correct download filename and MIME type.
Yes. Click Import OpenAPI, paste an OpenAPI or Swagger JSON spec, and the tool parses its paths into the endpoint editor — method, path, description, and parameters — so you can edit or re-export it in another format. A toast confirms how many endpoints were imported.