Compare the Top Free API Documentation Tools as of April 2025

What are Free API Documentation Tools?

API documentation tools are software tools that help developers create, maintain, and publish documentation for their Application Programming Interfaces (APIs). These tools streamline the process of explaining how to use an API, providing code examples, and outlining endpoints, parameters, and response formats. Many API documentation tools automatically generate docs from the codebase or integrate with frameworks to keep documentation up to date with API changes. They often include interactive features, like live testing or sandbox environments, allowing developers to experiment with API requests directly from the documentation. Ultimately, these tools improve the developer experience by making it easier to understand and use APIs effectively. Compare and read user reviews of the best Free API Documentation tools currently available using the table below. This list is updated regularly.

  • 1
    Docsie

    Docsie

    Docsie

    Docsie is an award-winning digital documentation and knowledge management platform based in Ontario, Canada. You can access Docsie through a SaaS web application to create & edit documentation from any location. Then, you can publish content to a dynamic knowledge portal that users can access whenever they need information! Docsie offers powerful business-grade features to write & manage product documentation: - Docsie Pilot onboarding - Custom portal design & optional training for paid plans - Internal & external portal for employees & end-users - Workspaces - Knowledge base analytics & user feedback collection - Free custom domain - Markdown import & export - WYSIWYG Editor - iFrame embed - SwaggerAPI import - Snippet, fragment, document & topic templates - Help center & in-app help interface - Guided tour builder - Version & language management - Webhooks - AI translation & content generation - Project management - RBAC/JWT/SSO for security
    Starting Price: $39 per month (annual)
  • 2
    Postman

    Postman

    Postman

    The collaboration platform for API development. Simplify each step of building an API and streamline collaboration so you can create better APIs—faster. Postman is a collaboration platform for API development. Postman's features simplify each step of building an API and streamline collaboration so you can create better APIs—faster. Quickly and easily send REST, SOAP, and GraphQL requests directly within Postman. Automate manual tests and integrate them into your CI/CD pipeline to ensure that any code changes won't break the API in production. Communicate the expected behavior of an API by simulating endpoints and their responses without having to set up a backend server. Generate and publish beautiful, machine-readable documentation to make your API easier to consume. Stay up-to-date on the health of your API by checking performance and response times at scheduled intervals. Provide a shared context for building and consuming APIs, and collaborate in real-time.
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    Starting Price: $12 per user per month
  • 3
    Zuplo

    Zuplo

    Zuplo

    We’re reinventing API management for everybody, from startups to enterprises. Add authentication, analytics, rate-limiting, and developer documentation to your APIs in minutes. Protect your API by adding rate-limiting with Zuplo in minutes, and add over 50 available plugins like authentication to your API with a single click. Zuplo was built on the edge and deployed to +300 data centers in the world, which makes multi-cloud deployments first-class. With Zuplo you can run different workloads in different clouds while enforcing a unified set of API policies. Zuplo is the only API gateway that runs your OpenAPI spec directly. Leverage the OpenAPI ecosystem to build your API, and then deploy it to Zuplo without additional configuration. Zuplo automatically generates beautiful docs for your API. You can customize the docs with markdown and devs can self-serve API Keys directly from your docs.
    Starting Price: $0 per month
  • 4
    Contentrain

    Contentrain

    Contentrain

    Contentrain is the first scalable content management platform combining Git and Serverless platforms. Harness the power of Git Architecture and the scalability of Serverless Platforms to streamline content management and collaboration on various digital platforms for developers and content creators. With the GIT version control system, collaboration is streamlined, while the integration of Serverless Platforms ensures real-time updates and scalability. Contentrain is the best solution for Markdown based content rich websites and also serves as a versatile solution for different use cases: - Document-driven web projects - Internal or external API Documentation - API references - Product overviews - Engaging marketing campaign websites - Modern startup landing pages - Jamstack websites - Multi language websites - RFP portals & Knowledge bases - PWA's - E-commerce websites - Blogs & Publishing platforms - Mobile application contents
  • 5
    Apidog

    Apidog

    Apidog

    Apidog is a complete set of tools that connects the entire API lifecycle, helping R&D teams implement best practices for API Design-first development. Design and debug APIs in a powerful visual editor. Describe and debug easily with JSON Schema support. Automate API lifecycle with Apidog's test generation from API specs, visual assertion, built-in response validation, and CI/CD. Generate visually appealing API documentation, publish to custom domain or securely share with collaborative teams. Local and cloud mock engine generate reasonable mock data according to field names and specifications without writing scripts. Quality tools have the power to unite your entire team, while ensuring that no task is needlessly repeated. Effortlessly describe your API as you test it, and generate JSON/XML schemas with a simple click. Generate test cases from APIs, add assertions visually, and create test scenarios with branches and iterations easily.
    Starting Price: $9 per user per month
  • 6
    Read the Docs

    Read the Docs

    Read the Docs

    Spend your time on writing high quality documentation, not on the tools to make your documentation work. Read the Docs simplifies software documentation by automating building, versioning, and hosting of your docs for you. We will host your documentation for free, forever. There are no tricks. We help over 100,000 open source projects share their docs, including a custom domain and theme. Whenever you push code to your favorite version control service, whether that is GitHub, BitBucket, or GitLab, we will automatically build your docs so your code and documentation are never out of sync. We build and host your docs for the web, but they are also viewable as PDFs, as single page HTML, and for eReaders. No additional configuration is required. We can host and build multiple versions of your docs so having a 1.0 version of your docs and a 2.0 version of your docs is as easy as having a separate branch or tag in your version control system.
    Starting Price: $5 per month
  • 7
    Mintlify

    Mintlify

    Mintlify

    Stop wrestling with outdated documentation. Integrate documentation into your CI/CD to move faster as you scale. Link your documentation with relevant code snippets and owners. Detect when documentation is out of date from code changes or user engagement. Configure alerts to be notified when documentation requires maintenance. Whether it is internal docs on Notion or external docs on ReadMe, we have integrations to support it. Be notified when documentation is out of date or resolve alerts when it has been properly updated. Detect how users engage with your documentation to improve its readability and clarity. Improve code readability without clustering your codebase with comments. Tag documentation ownership to those responsible of the code - or have it automatically detected.
    Starting Price: $40 per month
  • 8
    Treblle

    Treblle

    Treblle

    Treblle: A lightweight SDK for accelerated REST-based API development, see metadata for every API request with real-time API traffic monitoring, get powerful analytics and API governance features alongside API automated docs, and automated API security audits for every single request. Simplify workflows, enhance security with support for 18+ languages and frameworks for seamless integration. Empower your teams to build, ship, and maintain APIs faster.
    Starting Price: $99 per month
  • 9
    Bump.sh

    Bump.sh

    Bump.sh

    Bump.sh is the place for API developers to centralize all of their API documentation. Working with REST, Event-Drivent Architecture, or a mix of API technologies? Bump.sh is the only tool on the market that supports OpenAPI/Swagger, AsyncAPI, and soon more (such as GraphQL, SOAP, and gRPC). Plug Bump.sh into your CI, use our CLI, or upload your specification files manually, and benefit from a stunning UI that definitely contrasts with the legacy tools on the market. Enjoy all of the nifty UX details: we know devs will like it, as they were imagined by devs. Unique on the market: every time you publish a new version of your API documentation, Bump.sh automatically detects changes, publishes a changelog, and sends alerts to subscribe readers if the changes break anything.
    Starting Price: $149 per month
  • 10
    Docuo

    Docuo

    Spreading

    Docuo is an All-in-one tool documentation platform. It is a SaaS platform that helps you to build a great self-service knowledge base for your customers and internal users (public or private knowledge bases). It can Elevate your team's capabilities with one powerful documentation tool. Eliminate fragmented workflows, consolidate tasks, and supercharge efficiency. Benefits of using Docuo: —AI-Assisted Writing:Docuo Copilot automates documentation writing so developers can focus on coding, not writing. —Cross-Team Collaboration: Enable seamless collaboration so your developers and tech writers can co-create stellar documentation with ease. —Easy-to-use Editor: Intuitively embed images, videos, code and more. Customizable blocks make rearranging content effortless. —Hassle-Free Doc Management: Centralize docs for all products enabling effortless version control. —Publish Docs Sites: Docuo handles optimizations for responsiveness, mobile-friendliness and SEO
    Starting Price: $31/month/team
  • 11
    Stoplight

    Stoplight

    Stoplight

    Stoplight is an API Design, Development, and Documentation platform. Use Stoplight Platform to enable consistency, reusability, and quality in your API lifecycle, all with an easy, enjoyable developer experience. Here's what you can do with Stoplight Platform: - Design APIs with our easy visual designer, Stoplight Studio - Mock API designs automatically with Stoplight Prism mocking - Collaborate on your designs and invite internal and external users to provide feedback - Develop faster and better APIs - Test and enforce against style guides with Stoplight Spectral - Document both internal and external APIs automatically to create a delightful experience Utilize and integrate design-first workflows to quickly scale up standardized, collaborative, and well-governed API programs.
    Starting Price: Free
  • 12
    SwaggerHub

    SwaggerHub

    SmartBear

    SwaggerHub is an integrated API design and documentation platform, built for teams to drive consistency and discipline across the API development workflow. Accelerate your team’s design process without any loss in quality or organizational style consistency with a powerful Editor that’s fully compliant with the latest Swagger (OpenAPI) standards. A Powerful Editor equipped with smart error feedback and syntax auto-completion. Style Validators for ensuring design consistency across multiple APIs. API Mocking to virtualize operations without any code. Domains for storing, reusing and referencing common OAS syntax across multiple APIs. Have your API design and development centralized on a single location, allowing your teams to seamlessly collaborate on new APIs, or discover existing APIs on a centralized platform. Coordinate your entire API lifecycle from a central internal repository, hosted on the cloud.
    Starting Price: $90 per month
  • 13
    Hashnode

    Hashnode

    Hashnode

    Create and grow your developer blog, newsletter, or team engineering blog effortlessly with Hashnode. Level up your writing using powerful AI features. Blogging platform optimized for software developers and technical writers. Super-fast and SEO-optimized blogs built for developers and tech enthusiasts. Hashnode blogs are fast, up-to-date with SEO techniques, and score above 90 on all Lighthouse parameters. They're simple, elegant, and user-friendly. Own your traffic. Blog for free on a custom domain! Don't blog on rented URLs. Map your custom domain to your Hashnode blog for free and own your traffic. True content ownership. Automatic GitHub backup and publishing. Publish articles from your GitHub repository to your Hashnode blog and backup your Hashnode articles to GitHub like a pro. Create and scale developer documentation and API references that are as dynamic as your code. Built for teams that need full control, customization, and Stripe-level quality.
    Starting Price: $199 per month
  • 14
    Redocly

    Redocly

    Redocly

    Beautiful API documentation loved by teams and API consumers. At last, API documentation your whole team will be proud of. Publish beautiful API reference docs in seconds and style them in minutes. Tick every developer's favorite box right out of the box, three panels, a try-it console, generated code samples, SEO-friendly, even friendlier search. Nobody likes outdated docs and scope creep. Maintain API documentation with your favorite source control integrated with our cloud app workflows. We support them all, including on-premise and API management providers. Launch a developer portal in minutes reusing your API definitions as assets. Add tutorials, quick-start guides, and developer tooling with incredible customization. Validate, lint, and bundle multi-file API definitions. Write always on-spec OpenAPI documents. Plug in your API reference and customize every nook & cranny to wow your API consumers.
    Starting Price: $69 per month
  • 15
    Theneo

    Theneo

    Theneo

    Unlock the full potential of AI-powered API documentation. Create stunning, low-maintenance, and engaging docs with a single upload. Import your API collection manually or automatically with a little help from our integration tools for your favorite platforms like Postman. Whether you're building a REST, GraphQL or any other API, we've got you covered. Generates detailed descriptions and summaries for superior API documentation. Ensures flawless, up-to-date documentation. Effortless content search and auto code generation. Automatically update documentation when code changes. Extensions are available for Github, Gitlab, Bitbucket, VS Code, Postman, and more. Customize the appearance of your API docs. Adjust colors and visual elements to match your branding. Make documentation look like part of your website. Effortlessly create and maintain beautiful API docs with simple commands, right from your favorite development tools and source code editors.
    Starting Price: $120 per month
  • 16
    RapiDoc

    RapiDoc

    RapiDoc

    Free of any frameworks, setups, configs, build steps, or packaging. Can be used with any framework or just with vanilla Javascript. Style it to your heart's content. Change font, logo, colors, and theme. Inject external HTML or embed it into another HTML document. Create beautiful, customizable, interactive API documentation from OpenAPI specification. Use It just like any other HTML tag, Change its attribute using JavaScript and see it react to those changes. Basic knowledge of HTML is all that's required. Minimal dependencies, no runtime, and no virtual DOM ensure the lowest memory consumption, Just the native and raw speed of modern browsers. Loved by tech writers, designers, dev-ops, testers, and developers alike, due to its simplicity, interoperability, and powerful features. No special build-steps, runtime, or framework are required. Comes with built-in console to Try out the APIs. Supports authentication mechanism. No validation ensures you can test negative cases.
    Starting Price: Free
  • 17
    Qodex.ai

    Qodex.ai

    Qodex.ai

    Qodex.ai is an AI-powered platform that streamlines API testing and documentation, offering full automation without human intervention. Developed by and for developers, it enables users to add tests in plain English, eliminating the need for coding. The system automatically adapts as products evolve, ensuring continuous test coverage. Users can upload existing API files or utilize Qodex's SDK to create new ones, ready for testing in minutes. The AI learns the API and generates tests automatically, with the option to create custom tests by writing requirements in simple English. Tests can be run anytime, providing easy-to-read reports to quickly identify and fix issues. The platform also offers interactive API documentation, allowing users to ask questions and receive instant answers in an intuitive interface. It is a reliable tool for both front-end as well as back-end testing.
    Starting Price: $199 per month
  • 18
    Alphadoc

    Alphadoc

    Alphadoc

    Your open API spec is at the core of Alphadoc, create tutorials and intuitive sequence diagrams on top of it. Always in sync with your OAS spec through versioning. We will help you document your SDKs, long code snippets, and entire demo applications. Easily create code walkthroughs, combining API references, variables and more. Interactive docs let developers try out API calls with real data, and from your documentation and guides. With auto-updating endpoints on your pages, you can effortlessly describe API calls without the need for manual copying and pasting. We provide you with the building blocks to create intuitive documentation. You can also embed endpoints, diagrams and code walkthroughs in websites, blogs, or wherever you want.
    Starting Price: €150 per month
  • 19
    Penify

    Penify

    Penify

    Penify automates the software documentation process for Git repositories. Every time a code modification is merged into "main", Penify uses a Large Language Model to generate documentation for the updated code. This automation covers multiple documentation layers, including InCode Documentation, API Documentation, Architectural Documentation, and PR documentation, each designed to improve different aspects of the development process. By taking over the entire documentation process, Penify tackles the common problem of documentation becoming outdated as the code evolves.
    Starting Price: ₹835 per month per repository
  • 20
    Apiary

    Apiary

    Oracle

    Write an API in 30 minutes. Share it with your teammates or customers. Let them use the API mock to take your API for a spin--without writing any code. Iterate, rinse & repeat. Coding can wait until you know what your developers really need. DNA for your API, powerful, open sourced and developer-friendly. The ease of Markdown combined with the power of automated mock servers, tests, validations, proxies, and code samples in your language bindings. It's often hard to see how an API will be used until you have the chance to code against it. What wireframes are for UI design, a server mock is for API design. A quick way to prototype an API - even before you start writing code. Two clicks will link Apiary to a repository of your choice. It’s up to you whether you make the API Blueprint private or public and let the community contribute. We update API docs every time you commit, and we push commits to the repo whenever you update your documentation at Apiary. It's a virtuous cycle.
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