Best 10 Tools for Generating API Documentation in 2025

Theneo is an AI-native documentation platform that transforms how teams create and manage API documentation. Think of it as having an expert technical writer that works instantly - you provide your API specification files (like OpenAPI, Postman collections, or GraphQL schemas), and Theneo generates complete, interactive documentation automatically.

Postman is an all-in-one platform for working with APIs throughout their entire lifecycle. It provides tools to send API requests, view responses, write tests, create documentation, and monitor performance. Unlike basic HTTP clients, Postman offers a complete environment where teams can organize their work into collections, share them with teammates, and automate testing.

Mintlify is a documentation platform that transforms markdown files into polished, interactive websites. It works by connecting to your code repository and automatically building documentation sites whenever you make changes. The platform includes an AI assistant that helps write content, suggests improvements, and answers user questions directly in the docs.

Testfully is a platform that helps developers test and monitor APIs during development and after deployment. You can use it to send requests to your APIs, create automated tests, and set up monitoring to catch problems before they affect users.

Apidog is a platform that handles the complete process of creating and managing APIs. You can design your API structure, test how it works, create clear documentation, and share it with your team, all from one application.

Sanity is a content platform that stores your content as structured data and makes it available through powerful tools. Unlike traditional systems where content and design are locked together, Sanity keeps them separate. This means you create content once and use it anywhere - websites, apps, smart devices, or anywhere else you need it.

Firecamp is a multi-protocol API development tool that helps you test and build APIs with ease. Unlike traditional API clients that focus mainly on REST, Firecamp offers dedicated GUI playgrounds for REST, GraphQL, WebSocket, and Socket.IO protocols all in one application.

Insomnia is a desktop application that lets you test and work with APIs. Think of it as a specialized tool for developers who need to send requests to APIs and check the responses they get back. It supports all major API types, so you don't need different tools for different projects.

Strapi is an open-source headless CMS built with Node.js that delivers content through APIs instead of traditional web pages. Think of it as a smart backend system that stores and manages your content, then sends it anywhere you need through REST or GraphQL APIs.

Hoppscotch is an API development environment that runs in your web browser. You can test any API by sending requests and viewing the responses instantly. Unlike traditional tools, Hoppscotch is completely free and open-source, meaning anyone can use it or even contribute to improving it.