APIs are essential for making communication between applications possible, allowing businesses to scale higher through enhanced communications with servers. To ease the process of creating and maintaining API documentation, various tools are available that can help developers and technical writers design and unify documentation structure, provide quick solutions, save time and resources, define even simple concepts, and enable easy updates. Some popular free API documentation tools include Open API, ReDoc, Slate, DapperDox, and LucyBot DocGen, each with unique features such as interactive documentation, Markdown support, and customization options to suit different needs. These tools can help reduce complexity and improve the developer experience, making it critical for businesses to choose an effective documentation tool to achieve their goals.