An API documentation tool helps you reduce the time it takes for your developers to write and maintain documentation for your APIs, provide a common set of documentation that is used across all of your APIs and provide a consistent user experience for users from one API to another.
Documenting APIs used to be a hard task. The tools that document APIs are usually time-consuming and time-wasting for developers. But times have changed. There are now plenty of tools to help you document your APIs, right out of the box. This tutorial will walk you through the easiest way to document apis. So you can get started immediately.
If you are looking to create or maintain an API documentation, you have several choices. You can use a documentation tool with features that specifically target APIs or you can use general purpose documentation tools which support multiple formats.
For developers, it is a guidebook that describes the purpose and advantages of APIs and best practices for integrating them. In general, well-structured documentation should contain complete details on arguments, classes, return types, and functions. However, most developers and IT consultants will agree that integrating API documentation into your API ecosystem is anything but easy, especially when it concerns complex systems. In this case, an API documentation tool comes in very handy. We evaluated twenty-plus API documentation tools on the following factors.
- Document auto-generation from API definition
- Maintain multiple documentation versions
- Automatic documentation update
- Customization available
We have found the following API documentation tools to be the most effective based on the above factors.
Why API Documentation Matters
API documentation is human and machine-readable technical content that explains how a specific API works and what it is able to do. Its purpose is twofold. Firstly, it is an accurate reference source that describes the API in detail. Secondly, it can act as a guide and teaching tool that helps users get started and use it.
Done correctly, API documentation acts as the one true source of information for how an API works. It should contain details on functions, arguments, classes, and more in a structured format that is easy for both developers and non-technical users to understand. Often, it will include tutorials and examples, which will help the user better understand how the different parts work together.
Investing time and resources into creating high quality API documentation leads to many benefits:
- Reduced Onboarding Time – Customers and internal users can access the information they need to start using and benefiting from your API immediately.
- Reduced Reliance on Support – Good documentation reduces the strain on your API experts and helps other users find their own answers. This applies regardless of whether your API is internal-only or used by thousands of customers,
- Encourage Non-Engineering Users – By increasing the understanding of non-coding colleagues, your API documentation enables better discussions around how your APIs and data can be used to achieve your business goals.
- Increased Adoption Rate – Easy-to-use API documentation will increase the rate with which new users can start using your API. By providing a better user experience, businesses will benefit from increased word-of-mouth marketing, which leads to faster adoption.
- Improved User Satisfaction – Happy customers and colleagues improve your business’s reputation.
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Redocly sits comfortably at the top of this list because it supports OpenAPI v2 and Open API v3. It is also very flexible and highly customizable. Regardless of the activated mode, each end-user has full control over its responsiveness on mobile, color themes, fonts, and branding images.
The interface is clean and non-cluttered. The platform has been designed to focus on simplicity and functionality, which should be attractive to its users to use it regularly without feeling overwhelmed or intimidated by too many features.
Users can also use a wide range of extensions with this API documentation tool. This includes project logo URL, links to code samples, and integration with a Github repository.
The API documentation tool, which is based on React JS, has both free and paid versions. It also has incorporated in it a CLI that gives you access to all Open API definitions.
Although originally designed for large enterprises, it can also be used by individuals and small teams. In general, the pros of ReDoc.ly are;
- Highly customizable
- Packed with a lot of power
- Easy to deploy and use
- Has a gallery of rich and detailed document templates
Like every other platform, it has its own fair share of cons. Here they are:
- It can be a little pricey for individuals and small brands
- The low-end plans lack features
SwaggerHub is a favorite among techies and software developers. This is no doubt in connection to its ease of use, interactivity, fully hosted, and an array of other convenient features. It is more than just a documentation tool. Putting things in perspective, it has SmartBear support, an open-source API editor, and an interactive documentation tool.
SwaggerHub is a powerful visual tool that lets API providers create interactive documentation for their APIs, letting API providers see exactly how the contract will work before integrating it into any code.
The pros and cons of Swagger are as under.
- It has a free tier for indie developers and solopreneurs.
- It is quite easy to use, even for beginners.
- SwaggerHub has the capabilities to execute API calls from the documentation
- Can deploy API to AWS Lambda and AWS API Gateway
- The team plan is $90 a month when paid annually.
- Compatibility issues with cloud microservices
Spotlight is the way to go for a design-centric developer. Spotlight makes documenting your API easy with its built-in features. With automatic updates, accurate API documentation can be generated in a timely manner without having to manually update any of it yourself! Spotlight also helps you save time on the tedious task of updating and maintaining documentation for each change made to an API.
It also allows its end users the option to choose between JSON schema and openAPI-based API designs. A big plus of Stoplight is the ability to test designs out in real-time.
- Feature-loaded API design studio
- Optimized guide design features
- The free plan has limited design options
ReadMe is another favorite among many developers, thanks to its simplicity and ease of use. The tool also has several features that make it easy to generate streamlined documents.
Readme allows you to create beautiful, interactive API documentation with the power and convenience of a drag-and-drop editor. It allows API providers to add API keys directly in the docs and auto-generate code samples. This feature allows developers to make real API calls effortlessly.
ReadMe also has a rich gallery of documentation design templates.
- Interactive and responsible API development tool
- Pretty fast way of launching APIs
- Well loaded documentation design templates
- Limited third-party service integrations
Postman’s machine-readable API documentation tool makes it quite easy for developers to publish their documents quickly and on the go.
Postman’s API documentation builder is an easy way to create interactive and machine-readable API documentation. Postman allows developers to automatically pull in sample requests, headers, and code snippets for new or existing APIs to build docs quickly. Postman makes it easy to publish documentation with dynamic examples and machine-readable instructions.
- Proper communication with machine-readable comments
- Automatic updates on all API documents
- Complicated UI
- Steep learning curve
This is your best bet for non-commercial usage. It is highly customizable for amateurs and pros because it allows them to customize the documentation pages with HTML and Markdown.
- Highly customizable
- Simple to use
- Not ideal for individuals and small enterprises
DapperDox is an OpenAPI renderer with an open-source server. You can integrate OAS 2.0 and OAS 3.0 with their OpenAPI specifications via GitHub Flavored Markdown (GFM). Using the API explorer in the tool’s interface, users can tinker with the different document features available.
It is one of the easiest API documentation tools for bringing together guides, documentation, specifications, and diagrams.
- Very easy to use
- A rich gallery of themes
- Irregular updates
This API documentation tool creates API documentation from AsyncAPI 1.x, OpenAPI 2.0, and Swagger 2.0. A new feature on the documentation tool allows you to output HTML directly.
The interface shows a three-column page. The first, second, and third columns contain the explorer, description, and console, respectively. The console is a new feature on the platform for making API calls.
It has a rich lineup of templates that can be customized according to individual needs.
- Non-clustered UI
- Users can create HTML as well as markdowns
- Not so affordable
Just like the name suggests, OpenAPI Viewer is a powerful OpenAPI 3.0 and 2.0 spec, viewer. It also works with or without a framework. One of its biggest perks is its customization, branding, and personalization capacities. Putting things in perspective, one can add external contents like links, forms, images, and different forms of media to the top and bottom of their documents.
- Easily customizable
- Very easy to use
- Supports a lot of authentication like HTTP Bearer and HTTP Basic
- The free version doesn’t contain as many helpful features
RapidDoc has one of the best API documentation tools and UI interfaces. This interface is structured like that of SwaggerUI, such that you have a single column with collapsible bars. Each bar contains a console and its corresponding JSON payloads.
The flexibility of this tool allows you to customize the theme, colors, and font of your documents and UI interface. There is also a provision for embedding external HTML code in the document.
- Great looking UI
- Comes with a lot of themes
- Web component standard
- Integrated console
- Supports Markdown
- Does not support a wide range of extensions
What Makes a Great API Documentation?
Creating great API documentation is a delicate balancing act between providing detailed technical information and displaying it in a way that is easy to consume. The best way to see how it should be done is to look at examples of businesses that are doing well – thankfully, they’re not hard to find.
Many popular tools publish their API documentation online so that 3rd-party developers can get easy access to them. Stripe and Twilio are two great examples of documentation done right. Although their solutions are developed in-house, the best practice they display is still useful for businesses looking to create their own API documentation. Here are a few of the reasons why these sets of documentation are so effective:
- They provide example code in the documentation so that users can see how it works in practice.
- They make it easy to find solutions to common problems so that busy developers can get what they need quickly.
- They don’t provide unnecessary information that isn’t required to understand the API and how it works. When users are busy working and hit a problem, they want usable documentation, not extraneous information.
- They don’t assume a certain level of knowledge – the simplest concepts are as fully-explained as the most difficult ones.
- They are well-formatted. The content is organized and consistent and easy to read. This reduces friction for users who are looking to learn or solve a problem.
All the documentation tools discussed in this article can create API professional documentation. One can not explicitly deem any one tool as the best. The overall experience and requirements of an API documentation software depend on the user’s specifications, definitions, objectives, and documentation needs.
However, in our opinion, the Swagger restful API tool is considered best API documentation tool among all the tools mentioned due to their interactive user interface, ease of maintaining documentation, extensive range of tools and features for API consumers with any level of technical knowledge, and compatibility with a number of programming languages.