Compare the Top Free API Testing Tools as of April 2025

What are Free API Testing Tools?

API testing software is used to test and validate the functionality, performance, security, and reliability of Application Programming Interfaces (APIs). These tools help ensure that APIs perform as expected under various conditions and meet the required business and technical requirements. Features typically include automated testing, request/response validation, load testing, security testing (e.g., for vulnerabilities and authentication), and performance testing. API testing software often supports integration with continuous integration/continuous deployment (CI/CD) pipelines to facilitate automated testing as part of the software development lifecycle. Compare and read user reviews of the best Free API Testing tools currently available using the table below. This list is updated regularly.

  • 1
    ZAPTEST

    ZAPTEST

    ZAPTEST Inc.

    ZAPTEST is a leading Free and Enterprise software test automation and RPA tool. Offerings include Computer Vision technology that allows for Cross-Platform digital interface automation for UI, API, Load testing, and RPA in a seamless process. Combine that with our 1SCRIPT methodology, seamless automation, parallel execution, and unlimited licenses– you get an efficient testing suite that generates up to 10X ROI. We promise that if you can perform a procedure via any digital interface (live application or mockup) manually, ZAPTEST can automate this procedure As-Is! With ZAPTEST’s Enterprise Solution subscription program, you receive unlimited licenses across the entire organization. Regardless of whether your automation needs increase, your cost remains fixed. FARM allows ZAPTEST users to manage all of their devices so you can remotely control cross-environments and projects from any location. ZAPTEST uses many practical applications to enhance its software testing software capabilities
  • 2
    Katalon Studio
    An all-in-one test automation solution Get started in no time, scale up with no limit, for any team, at any level. Katalon Studio Robust test generation on all platforms Productive IDE to generate automated tests easily for all platforms and OSs, regardless of application complexity. Powerful recording utility for effortlessly storing all UI elements to maximize reusability. Codeless experience for beginners. Infinite testing extension for experts. Set Up Projects Built-in project templates Start immediately with ready-made templates, test case libraries, keywords, and object repositories. All kinds of end-to-end testing in one place Uniquely perform web, mobile, API, and desktop testing – all in a single project.
  • Previous
  • You're on page 1
  • Next