APITree is described as 'free cloud-based API tool to create, manage and share OpenAPI specifications. It converts your OpenApi v2 / v3 specification into a beautiful technical API documentation. Public API documentation is hosted for free'. There are more than 10 alternatives to APITree for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and SaaS. The best alternative is Postman, which is free. Other great apps like APITree are Thunder Client (Free), APId (Free, Open Source), Stoplight (Free Personal, Open Source) and RESTer (Free, Open Source).
Postman is a tool that facilitates the development and use of APIs. Postman provides all the functionality needed to create or simulate API specifications and use the Postman Collection Runner to create tests.
RestCase is a security-focused API development platform that enables its users to rapidly create secure microservices, mock them in order to start testing, monitor APIs and collaborate on their development and testing.
Hitman is built to Collaborate, Develop, & Publish Better APIs – FASTER. Share your work in a dedicated workspace and invite your teammates to collaborate. Real-time collaboration and faster feedback cycles to help you build effectively.