# API Doc Generator

Generate polished API documentation from OpenAPI or annotated comments

> Canonical page: https://elysiatools.com/en/tools/api-doc-generator

- **Category:** Development

- **Keywords:** api, openapi, swagger, documentation, html, markdown, pdf

## Overview

Generate polished API documentation from OpenAPI/Swagger specs or structured code comments.

**Output formats**
- Interactive HTML
- Markdown
- PDF

**Included sections**
- Endpoint overview
- Parameters and request body
- Response examples
- Error code reference

## Inputs

- **API Source** (textarea): Paste OpenAPI JSON/YAML or annotated comments here...
- **Source Format** (select)
- **Output Format** (select)
- **Document Title** (text): API Reference
- **Theme** (select)
- **Include Examples** (checkbox)
- **Include Schemas** (checkbox)

## When to use

- Transforming machine-readable OpenAPI specs into human-friendly reference guides
- Converting inline code annotations into shareable documentation formats
- Producing offline-ready PDF or web-ready HTML docs for stakeholders

## How it works

- Paste your OpenAPI JSON/YAML or structured annotated comments into the API Source field
- Select the output format (Interactive HTML, Markdown, or PDF) and configure options like title and theme
- Toggle inclusion of request/response examples and schema definitions as needed
- Download the generated documentation file with organized endpoint sections and parameter tables

## Use cases

- Publishing developer portals from OpenAPI specifications
- Creating internal API guides from annotated source code comments
- Distributing printable PDF reference sheets to integration partners

## Frequently asked questions

### What input formats does the generator accept?

OpenAPI JSON, OpenAPI YAML, and structured annotated comments.

### Can I change the appearance of the HTML output?

Yes, choose between Slate or Paper themes in the Theme selector.

### Is it possible to exclude code examples from the generated docs?

Yes, uncheck the Include Examples option to omit response samples.

### Does the tool support auto-detecting OpenAPI versions?

Yes, set Source Format to Auto Detect to parse JSON or YAML automatically.

### Can I generate a PDF suitable for printing?

Yes, select PDF as the Output Format for a print-ready document.

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- [Encrypted PDF Converter](https://elysiatools.com/en/tools/encrypted-pdf-converter): Open password-protected PDFs with OpenDataLoader and export them as Markdown, JSON, or text once the correct password is provided
- [Markdown to PDF Theme Pack](https://elysiatools.com/en/tools/markdown-to-pdf-theme-pack): Convert Markdown to PDF with dark, light, or print-ready themes

## Samples

- [Markdown Slide Deck Samples](https://elysiatools.com/en/samples/md-slide-deck-to-pdf): Remark/Marp style Markdown slide decks for testing PDF export layouts
- [PDF Samples](https://elysiatools.com/en/samples/pdf-samples): Generated PDF samples from tools dated 2026-02-01 to 2026-02-10
- [Markdown Samples](https://elysiatools.com/en/samples/markdown-samples): Markdown format examples from simple to complex document structures
- [Markdown Viewer Samples](https://elysiatools.com/en/samples/markdown-viewer-samples): Sample Markdown files for README preview, documentation rendering, and rich-text markup tests

## Related content

- [Documentation Authoring, Review, and Publishing](https://elysiatools.com/en/hubs/documentation-authoring-publishing): Extract source material from code, PDF, or HTML, then assemble, review, preview, and export a publishable documentation set.
- [API Contract Definition, Schema Validation, and Change Testing](https://elysiatools.com/en/hubs/api-contract-testing): Define an API contract, validate schemas and captured payloads, detect compatibility risks, and record test acceptance.
- [OpenAPI Utility Workflow](https://elysiatools.com/en/hubs/openapi-utility): Generate OpenAPI types and docs, review breaking changes, validate responses, and harden the contract with stress and mutation tests.