You could document APIs manually or use a documentation tool for that. API has specifications for each type of API. For REST APIs, there is the Open API Specification, and for GraphQL APIs, there is a Schema Definition Language.

Creating API documentation manually is tedious. It is better to auto-generate your API documents using API document tools. These API tools could design your documentation and make it more presentable and appealing to your readers.

There are so many tools out there for API documentation. This article aims to highlight some of the best API documentation tools.

Why you need API documentation tools

• API documentation tools aim to speed up the documentation process. They can generate documentation from an API, making it faster for you to document your APIs efficiently and keep up with changes in the APIs.

• These tools help to organise and structure documentation, making it easier for writers to write their documentation clearly and logically.

• Every API document needs to be up-to-date so these tools provide features that record and update changes and also promote collaboration.

• They provide design features to style the user interface of the documentation. Which improves the user experience for developers reading the documents.

• API documentation tools can provide examples or use cases based on real-life scenarios of the API to help you write better.

Generally, these tools make it easier for writers to create organised documentation. They also make it easier for developers, product managers, and other team members to use APIs effectively.

Best API documentation tools

The best API documentation tools that have brilliant uses and benefits are:

• Swagger
• Postman
• Readme
• Stoplight
• Redocly

1. Swagger

Swagger has so many features that make API documentation seamless, which is why developers and writers love it.

It generates documentation automatically from OpenAPI definitions. It also designs your documentation with an amazing interface to reveal an aesthetic appeal using SwaggerUI.

Swagger provides versioning, which is a great way to maintain and easily update your documentation.

With Swagger, you can run tests and deploy your documentation with ease.

Pricing

Swagger has many tools like swagger codegen, swagger explore and so on which are free. However, there is a separate pricing for swagger hub.

Swagger hub

It has a free plan for a single user
Offers €84/month for a team
Get in touch for custom pricing.

2. Postman

Postman is a great API management tool that not only tests APIs but also generates documentation from APIs.

With Postman, you can generate content from your API, and it updates your documentation whenever you make changes to your API.
Postman promotes collaboration among teams by making it easy for you to share documentation.

Pricing
Has a free plan.
Paid plans begin at $12 per month.

3. ReadMe

ReadMe is a great API documentation tool for generating documentation. It embraces the docs as code approach, making it easier for you to update changes.

It also hosts your documentation for you, removing the headache of paying for storage.

ReadMe has a rich user interface that supports markdown, and it provides an API explorer for your users to test-run the APIs. It offers analytics for you to access your documentation performance and customer support.

Finally, ReadMe is one of the best API documentation tools, loved by developers, and has a large developer community.

Pricing
It has a free plan with access to limited features.
Paid plans start at $99 per month.

4. Stoplight

Stoplight is an API documentation tool that has beautiful design features. It is tagged "design-first" because it auto-generates your documentation using great design themes.

Stoplight hosts your documentation on its server, which reduces the hassle of hosting on a different server.
It also provides a style guide editor that lets you document your APIs efficiently.

Stoplight has consoles you could use to preview your documentation, although you cannot monitor your documentation's performance.

Pricing
It has a free trial that offers limited features.
Paid plans begin at $99 a month.

5. Redocly

Redocly is an API documentation tool that integrates with git for Docs-as-Code. It also lets you preview your changes before you merge them.

With Redocly, you could easily set up your API documentation pipeline and deploy it to any platform of your choice.
It is designed for both developers and writers.

It integrates with CI tools, making it possible for you to test and update your changes in a secure environment.

Although using Redocly requires technical knowledge, it has well-detailed documentation that serves as a guide.

Pricing
Has a free plan for creating reference documents.
Paid plans start at $69 a month.

Factors to consider in the quest for API documentation tools

Some factors to consider in finding API documentation tools are:

Seamless Integration

Consider tools that integrate easily with other tools like version control systems, continuous integration systems, and so on.

Ease of use and customization

Choose tools that have a great user experience. Tools that accelerate your work rate and that you could easily customise to your taste.

Support

Always consider tools that provide resources on troubleshooting and, if possible, tools with a great developer community.

That way, you can always get help from the community when you need it. Companies usually place their customer service behind a paywall; if you can get it, then that would be helpful too.

Security

Security is important in API management. When working with APIs, look for tools that focus on and enforce security to avoid unwarranted attacks.

Pricing

Choose tools that can offer you what you need on an affordable budget. These tools normally offer free and paid plans. It is up to you to select which of the plans would be realistic for you and within your budget.

By considering these factors, you can choose an API documentation tool that fits your needs and helps you create comprehensive and accessible documentation for your APIs.

Closing Thoughts

That sums up the five best API documentation tools. These tools are for generating documentation from your APIs and beautifying it.
There are other tools you could use to test your API documentation against your API response, and they are Dredd, Cherrybomb, and so on.