API Fortress is described as 'Automated API testing for the entire lifecycle. No coding, web-based, actually works'. There are more than 10 alternatives to API Fortress 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 API Fortress are soapUI (Free, Open Source), Thunder Client (Free), APId (Free, Open Source) and Stoplight (Free Personal, 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.
Runscope helps you monitor, log and measure API usage to solve API problems fast. Automatically monitor APIs without any coding. Runscope provides complete logging for all of your API traffic. Track down troublesome API calls with powerful search.
Bearer is a developer tool that helps engineering teams monitor API requests, track performance, detect anomalies, and fix issues for their critical API usage. The solution monitors all outgoing API requests without proxying traffic.
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.
Assertible is the easiest way to test and monitor your APIs and helps reduce bugs in web apps by providing tools to continuously validate endpoints and responses with a flexible interface to run your tests any time and place.