API documentation is often the first point of contact with new users. It’s also one of the most important elements in delivering a positive user experience (UX) and developer experience (DX). It’s no exaggeration to say that API documentation is one of the most important aspects of an API. This makes API documentation tools essential.

API documentation tools have come a long way in recent years. There have been some exciting developments in the API documentation space, including everything from AI tools for creating APIs directly from the documentation to documentation tools for API-first design. We’ve compiled a list of ten of our favorite tools for API documentation.

1. Apiary

Interactive API documentation benefits both API producers and consumers. Helpful API documentation improves UX by offering real-world examples of an API in action. For API developers, interactive API documentation makes any errors or inaccuracies in the API documentation immediately obvious.

Apiary is a popular tool that creates interactive API documentation from simple Markdown as long as it’s written in API Blueprint or Swagger format. Apiary has its drawbacks, though. For starters, you can only create one project on the free tier. It also must be made public. If you’re looking for a solution that can create private API documentation, you might do better looking elsewhere.

2. Slate

Slate is another open-source API documentation tool that generates beautiful, clean minimal API documentation from Markdown. Patterned after the documentation from PayPal and Stripe, its side-by-side formatting delivers the entire documentation on a single page. It also offers native support for code syntax in over 100 languages. It also lets you easily switch between programming languages if your API has bindings in multiple different languages. Slate documentation is maintained through GitHub pages, making it a good pick for collaborative API projects.

3. SwaggerHub

The OpenAPI Specification (OAS) is one of the most popular API specifications in today’s API marketplace, thanks to it being language agnostic and free to use. That makes SwaggerHub especially popular, as it’s built and maintained by SmartBear, the company initially responsible for donating OAS.

SwaggerHub doesn’t just support OAS, either. It also supports AsyncAPI, another popular and powerful API specification. SwaggerHub lets you create reusable blocks, custom code, and mockups and then deploy them in multiple languages. Detailed cataloging makes finding assets across multiple APIs easy, making it an excellent choice for anyone managing multiple APIs.

4. DapperDox

DapperDox is another excellent API documentation tool for working with OAS. The tool lets users combine API documentation and guides into one interactive website, greatly improving UX and DX simultaneously. It also supports GitHub-Flavored Markdown, letting you integrate your API documentation and GitHub pages effortlessly. DapperDox even lets API developers create a proxy for their developer platforms, making it an excellent option as a one-stop solution for getting started with an API.

5. Knowl.ai

2024 has seen great strides in AI-driven APIs. Knowl.ai can create API documentation directly from your code, ensuring that your API documentation is always up-to-date and correct. It can even be connected directly to your code repositories. Knowl.ai can also provide developers with code snippets, request examples, lists of parameters, and authentication details.

6. Docusaurus

Docusaurus is a powerful open-source API documentation generator created by Meta. Like Apiary and Slate, Docusaurus creates rich, appealing interactive API documentation directly from Markdown. Docusaurus goes above and beyond simply creating documentation, though. It also supports versioning, search, localization, and blogging.

7. Apidog

A design-first approach to API development has been getting increasingly popular in recent years, mainly due to its consistency and focus on delivering business goals. Apidog is a popular, powerful tool for API-first design. It’s got a clean, user-friendly interface, making it a good choice for developers with limited technical experience. It’s also an all-in-one API development platform, offering everything from collaborative API documentation to a debugging environment. If you are looking for a solution for API-first design that also functions as a complete API development environment, Apidog is worth a look.

8. Redoc

Redoc is another tool that creates clean, attractive API documentation directly from an OpenAPI specification. The tool features a three-panel layout, making the most important information available in one glance. It also lets developers group APIs together using the x-tagGroups extension. Redoc is remarkably capable for a free, open-source API documentation tool.

9. Gitbook

Gitbook started as a tool for managing Git repositories. It has since evolved to become a robust API documentation tool with enough special features to make our list of the best API documentation tools. Content auditing is an especially useful feature that identifies and resolves conflicting information in your documentation. It also supports embedding content into your documentation, allowing developers to include everything from code sandboxes to demos and interactive elements. The ability to customize documentation with custom themes, scripts, and integrations makes Gitbook a good choice for API producers looking to create attractive, appealing API documentation.

10. DevDocs

Both API developers and consumers alike rarely use just one API. Recent analysis suggests that large enterprises use an average of 300 APIs. It’s not practical to have to sort through all that API documentation.

DevDocs is an open-source API documentation tool that can combine multiple documents into a clean, well-organized web UI that can be easily searched and sorted. DevDocs even offers offline support.

Honorable Mentions

• Stoplight: Stoplight is another popular API documentation tool that doubles as a fully-fledged API development environment.
• Readme: Readme is a tool for designing interactive APIs that also provides analytics and insights into user behavior, allowing you to optimize both your API and API documentation alike.
• Mintlify: Mintlify is a clean, well-designed API documentation generator with an excellent playground feature.
• RapiDoc: Rapidoc is an API documentation generator that creates documentation from an OpenAPI specification.
• Bump.sh: Bump.sh is an API doc platform for tech writers and engineers. It particularly excels at a specification-driven approach to API documentation.
• Zudoku: Zudoku is an open-source, OpenAPI-powered, highly customizable API documentation from Zuplo.

Final Thoughts on the Best API Documentation Tools for 2024

API documentation tools can make all the difference in API adoption. If users find your API challenging to use or understand, they’ll quickly turn to one of your competitors. It’s also one of the most important aspects of a positive DX, giving developers what they need to effectively use your API.

Different API documentation tools are better for certain needs than others. If you’re looking for a tool to create API documentation from Markdown, you might want to try Apiary or Slate. For teams desiring a popular, widely-used documentation tool, try SwaggerHub. If you want a tool that can leverage AI for API documentation, try Knowl.ai. If you need a solution for managing and maintaining many different API docs, try DevDocs. Whatever your API documentation needs, at least one of our ten best API documentation tools for 2024 should do the trick!

Considering how important developer experience is, you should focus on your API documentation as much as any other aspect of your API, if not more. With these API documentation tools, you’ll be able to create and maintain API documentation without having to spend a ton of time, money, energy, or resources.