Compare the Top Free API Testing Tools as of December 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.

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    Cerberus Testing

    Cerberus Testing

    Cerberus Testing

    Cerberus Testing is a low-code software testing automation enabling continuous testing at scale. Using the solution you can remove years of implementing an internal testing framework. The product enables you to quickly iterate through your testing lifecycle, from test repository, execution, reporting and analytics. The solution allows the collaboration of the teams from the use-cases definition to the test case execution on the variety of browsers, devices, apps and APIs. You can leverage your own or external robots infrastructure to execute your test at scale, enabling you to focus on your business value. It supports various integrations for speed of implementation such as Jenkins, Bitbucket, Slack, Kafka. It is available and maintained in open-source by various digital and retail players such as La Redoute, Decathlon, Adeo, and Norauto.
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    Starting Price: €0
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    Ambassador

    Ambassador

    Ambassador Labs

    Ambassador Edge Stack is a Kubernetes-native API Gateway that delivers the scalability, security, and simplicity for some of the world's largest Kubernetes installations. Edge Stack makes securing microservices easy with a comprehensive set of security functionality, including automatic TLS, authentication, rate limiting, WAF integration, and fine-grained access control. The API Gateway contains a modern Kubernetes ingress controller that supports a broad range of protocols including gRPC and gRPC-Web, supports TLS termination, and provides traffic management controls for resource availability. Why use Ambassador Edge Stack API Gateway? - Accelerate Scalability: Manage high traffic volumes and distribute incoming requests across multiple backend services, ensuring reliable application performance. - Enhanced Security: Protect your APIs from unauthorized access and malicious attacks with robust security features. - Improve Productivity & Developer Experience
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    Alithya GoTest
    Alithya GoTest is a collaborative test hub that is easy and quick to master and integrate, ensuring the quality of any professional digital solutions for companies requiring reliability without compromises. Ensure the quality of your application without sacrificing speed or agility with an easy-to-use, GUI test automation tool. Whether using scripts or not, our flexibility is unmatched, letting you create manual, automated or hybrid test suites for every desktop, web, and mobile application with ease including .Net, Java, WPF and Windows 10, modern JavaScript frameworks like React and Angular and iOS or Andoid with 2050+ browser and platform configurations. No need to jailbreak your devices. Alithya GoTest comes with a keyword library of over 1500 keywords, so you can ensure your GUI and API tests are scalable, robust, and easy to maintain. Alithya also offers consulting, coaching and training to ensure the success of your teams.
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    HttpMaster
    HttpMaster is a debugging and testing tool for various HTTP applications with special focus on web APIs and RESTful web services. Key features: - HttpMaster project to store complete definition of HTTP calls in one single place. - Broad set of HTTP properties (HTTP headers, URL encoding, etc.). - Dynamic parameters to simulate variations of input data or create global API values. - Response data validation with logical expressions. - Request chaining to use data from previous request with the next request. - Extensive data upload support, including 'multipart/form-data'. - Request data builder for creating request body with an optional dynamic parameters. - Request item execution with detailed progress monitoring. - Execution groups to create batches of requests. - Comprehensive execution data review and management. - Basic request tool for ad-hoc execution. - Command line interface. - PDF reports. - Support for cURL commands.
    Starting Price: Starting from $69
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    Telepresence

    Telepresence

    Ambassador Labs

    Telepresence streamlines your local development process, enabling immediate feedback. You can launch your local environment on your laptop, equipped with your preferred tools, while Telepresence seamlessly connects them to the microservices and test databases they rely on. It simplifies and expedites collaborative development, debugging, and testing within Kubernetes environments by establishing a seamless connection between your local machine and shared remote Kubernetes clusters. Why Telepresence: Faster feedback loops: Spend less time building, containerizing, and deploying code. Get immediate feedback on code changes by running your service in the cloud from your local machine. Shift testing left: Create a remote-to-local debugging experience. Catch bugs pre-production without the configuration headache of remote debugging. Deliver better, faster user experience: Get new features and applications into the hands of users faster and more frequently.
    Starting Price: Free
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    BlazeMeter

    BlazeMeter

    BlazeMeter

    BlazeMeter’s open-source based, enterprise ready platform unifies all the functionality you need to shift testing left - and right. Use our intuitive UI to create tests or reuse your existing scripts and run them at scale as part of your continuous testing strategy. Test and generate detailed reporting and see historic trends. Spend more time innovating & less time maintaining your toolchain. Continuous testing is key to delivering with quality, volume, and velocity. But integrating, maintaining, learning and switching between multiple tools wastes valuable time and resources. BlazeMeter makes it easy with a super intuitive platform that does it all. BlazeMeter delivers complete shift left testing, so you can wow the marketplace with innovation. BlazeMeter provides all the components you need for shift left continuous testing. Work with CLIs, APIs, UI, open source tools, and more. Save HUGE time with setup, maintenance, learning, and day to day use.
    Starting Price: $149 per month
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    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.
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    Keysight Eggplant

    Keysight Eggplant

    Keysight Technologies

    Keysight Eggplant is an AI-powered software testing platform that helps teams automate functional, regression, and performance testing across any system or platform. Built to eliminate repetitive manual testing, it ensures faster releases, broader coverage, and higher-quality applications. With capabilities spanning UI, performance, and mobile app testing, Eggplant allows organizations to validate real user experiences using computer vision and OCR-based automation. It seamlessly integrates into CI/CD pipelines like Jenkins, Azure DevOps, and GitHub for continuous testing at every code check-in. Supporting technologies from legacy GUIs to cloud-native apps, it delivers consistent reliability across complex environments. Trusted by global enterprises and organizations such as NASA, JetBlue, and the US Army, Keysight Eggplant enables smarter testing and better software outcomes.
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    KeyRunner

    KeyRunner

    Launchiam

    The Platform to Build, Test & Secure APIs. Transform how you design, test, and manage APIs. Collaborate easily, run tests locally, and protect sensitive data every step of the way. No Signup or Login Get started instantly—no need for lengthy sign-ups or logins. VS Code Extension & Desktop Apps Work where you're comfortable! Our VS Code extension and desktop apps integrate seamlessly with your existing workflow. Local Storage & Execution Keep data secure with local storage and execution, ensuring sensitive information stays on your device. Run Unlimited Collections Test and manage unlimited API collections, enabling effortless scaling for all your projects. Mock Servers Streamline development by creating mock servers for fast testing and API response simulation. Scriptless Testing & Playground Simplify testing with our user-friendly interface—experiment with APIs without writing any code. Our enterprise features take it even further. Contact us!
    Starting Price: $39/month/user
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