With APIs accounting for 83% of web traffic, organizations have been pouring more resources into API development to add additional revenue streams, streamline processes, and improve business outcomes.

The value of your APIs depends on your adoption rates - without an active user base, your chances of succeeding are slim.

API documentation plays a considerable role in improving adoption rates by providing API consumers with instructions on using and integrating your APIs.

But that's the case only if you provide API documentation tools that help your API consumers use your APIs more effectively.

This article ranks and reviews the best API documentation tools based on their features, pricing, and collaboration toolset.

What Are the Best API Documentation Tools?

Here are our top picks for the best API documentation tools to use this year:

1. Postman
2. Swagger UI
3. ReadMe
4. Stoplight
5. RapidDoc

1. Postman

Postman is a powerful and popular platform that helps developers build, test, and document APIs.

Its API documentation tool enables you to generate machine-readable documentation to keep your APIs fresh and accurate with automatic updates.

Postman is a top choice for many API development teams with its user-friendly interface and robust features.

Key Features

• Auto Updates - Each time you make any changes to your API, the platform automatically updates your API documentation, ensuring your docs are always up-to-date.
• Machine-readable Documentation - Postman allows you to create structured API documentation to make it processable by applications, saving you time and dev resources.
• Powerful Collaboration Tools - Postman provides everything large teams need to collaborate in the cloud, promoting innovation and collaboration seamlessly.
• The "Run in Postman" Button - This unique feature allows third parties to import your collection in just a few clicks.

Pricing

The pricing packages are pretty straightforward, allowing you to seamlessly scale as you grow:

• Free - Postman offers a free plan that provides access to the core functionalities of the platform for up to three users. 
• Basic ($12/mo per user) - This pricing plan unlocks all collaboration tools, ten powerful integrations, a 30-day window for deleted collection recovery, one custom domain, and  10,000 monthly calls to Postman API.
• Professional ($29/mo per user) - The plan contains everything included in Basic while unlocking the features that medium-sized teams need, including workspaces, basic user roles and permissions, and 100,000 calls to Postman API.
• Enterprise ($99/mo per user) - This plan provides large companies with the tools they need to take their API development to the next level, including 100+ integrations, public API governance, and advanced reporting tools.

Why we recommend this tool: Postman is one of the most popular API management platforms both for individual developers and large teams. The API documentation tool is well-polished and can be easily integrated into virtually any ecosystem.

2. Swagger UI

Swagger UI is an API documentation tool that helps developers quickly create, visualize, and understand their APIs.

The platform removes the manual work of documenting APIs, allowing you to save precious dev resources and streamline your development process.

Top Features

• Dynamic API Documentation - Swagger UI makes it easy to generate and maintain user-friendly docs to save your development team time and resources.
• API Mocking - Make a mock API to test your requests and responses to ensure the high accuracy of your API documentation.
• Hosted API Documentation - Swagger UI allows you to create interactive API documentation hosted on the platform to ensure high-security standards and user-friendliness.
• Import Your API Documentation - Move your existing OAS definitions to Swagger UI to boost adoption rates.

Pricing

The platform offers three pricing plans.

Each of them has included, but you may want to switch to one of their pricing plans to unlock advanced integrations, collaboration features, and more:

• Free - This plan provides access to the core API documentation functionalities for one user.
• Team ($75/mo per user) - This pricing package unlocks advanced integrations, collaboration features, as well as chart and email support.
• Enterprise (a custom quote) - The pricing package is geared towards large teams looking for sophisticated tools for scaling their API development, including API standardization, on-premise installation, and SSO to ensure high-security standards.

Why we recommend this tool: Swagger UI is an excellent option for large teams looking to scale their API development efforts.

3. ReadMe

ReadMe is a flexible API documentation tool that empowers developers to create interactive API documentation.

The dashboard looks great right out of the box, providing a stellar user experience with an easy-to-use set of tools.

With ReadMe, you can use their drag-and-drop editor to build robust API documentation, giving developers everything they need to get started in no time.

Top Features

• API Analytics - Track developer metrics to better understand and serve your API consumers from status codes to usage graphs.
• API Explorer - Enable your users to test how your APIs work right on the API documentation pages.
• Drag & Drop - Get up and running in minutes by setting up your docs and landing pages using the built-in theme builder and markdown editor.
• Customization - Use CSS to create a fully custom API documentation hub to align it better with your brand and digital assets.
• Community Building Tools - From support forums to Q&As, connect with your user base on a deeper level to improve your APIs and boost your adoption rates.

Pricing

ReadMe offers flexible pricing packages to make the platform accessible to small teams and large organizations alike:

• Free - Test out the platform with the core features unlocked, including five admin users, three API versions, and a 30-day metric history.
• Startup ($99/mo per project) - This plan entails everything included in Free along with custom pages and domains and the ability to create changelogs and support forums.
• Business ($399/mo per project) - This plan unlocks custom CSS, 404 redirect rules, and removes the ReadMe logo, helping you brand your API documentation however you see fit.
• Enterprise ($2,000/mo per project) - This pricing package unlocks a broad spectrum of critical features for large teams, including OAuth 2.0 authorization, multi-language support, and custom JS.

Why we recommend this tool: ReadMe is a specialized API documentation tool that removed a lot of manual work for small teams, helping them focus on building their API.

4. Stoplight

Stoplight is a specialized API documentation platform that allows users to describe their APIs without enduring a steep learning curve.

By publishing interactive documentation, tutorials, and code samples using Stoplight, you can help internal and external users discover, learn, and use your APIs much more effectively - which boosts your API adoption rates.

Top Features

• Developer Hub - Consolidate your public and private API docs in one place to make your APIs more manageable.
• Flexible Branding Tools - Stoplight offers powerful theming toolsets to make your API documentation hub congruent with your brand styling.
• Granular Search Functions - Stoplight supports hub-wide search, making it easy for developers and API consumers to navigate your API documentation - regardless of its size and complexity.
• Code Samples - Drastically shorten the learning curve for your API users by providing them with pre-built code samples and SDKs.

Pricing

Stoplight offers four pricing plans based on your unique API documentation needs.

• Free - a free plan with limited functionalities and the ability to create up to two projects.
• Starter ($79/mo) - This pricing plan unlocks a wide range of features, including versioning and theming
• Professional ($319/mo) - This pricing package includes LDAP & SAML SSO, activity logs, and up to 50 guests.
• Enterprise (a custom quote) - A custom pricing plan designed for large organizations.

Why we recommend this tool: Stoplight has everything you need to scale your API documentation along with your APIs without any disruptions.

5. RapidDoc

RapidDoc is one of the best API documentation tools available to help you quickly document your APIs with interactive and responsive docs.

The platform provides an intuitive UX, allowing developers to get started right away while offering a wide range of features to make the process of documenting your APIs more manageable.

Here's a quick sample showing you how RapidDoc API documentation looks like:

Top Features

• Supports Swagger 2.0 & OpenAPI 3.x.x - RapidDoc supports the most popular API documentation formats and frameworks.
• Intuitive User Interface - The developers went above and beyond to create a seamless UX, including auto-expanding all examples to minimize the average number of clicks needed to navigate your API docs.
• Powerful Branding Functionalities - From fonts to logos, you are in control of the look and feel of your API documentation.
• Fast Performance - No virtual DOM, no runtime, and minimal dependencies ensure low memory consumption and fast performance.

Pricing

RapidDoc is free to use.

Why we love this tool: RapidDoc has everything you need to set up your API documentation without the need to pay for maintaining your docs.

FAQ: API Documentation Tools

What Are API Documentation Tools?

The purpose of API documentation tools is to make it easier for developers to design, document, and publish APIs.

API documentation tools can improve your overall API development process by helping you write - or even automatically generate - clear and easy-to-follow documentation.

Most API documentation tools can also generate machine-readable descriptions, helping save development resources on maintenance and versioning.

Why Is API Documentation Important?

API documentation is necessary because it can help improve the adoption rate of your APIs by making them accessible to both developers and non-technical users alike. The easy-of-use of your APIs is especially important as citizen development becomes more prevalent in the digital age.

Good API documentation should include a clear description of the endpoint, input and output parameters, response codes, API specifications, and any other relevant information. 

Best Practices for Writing Good API Documentation

Use the following best practices to create API documentation that moves the needle:

• Make your API documentation accessible for non-technical users
• Eliminate or minimize technical jargon
• Encourage feedback from your users
• Describe the most common use cases with examples

Protect Your APIs with APIsec

While documenting your APIs is crucial, protecting them. 

To keep your APIs protected from data breaches and other cyber threats that can wreak havoc on your reputation, APIsec developed an AI-based API security testing solution for automated, comprehensive, and continuous API testing.

Want to find out more? Sign up to get a free vulnerability assessment, or contact our team today to schedule a free consultation.