Best Free API Testing Tools of 2025 - Page 3

Find and compare the best Free API Testing tools in 2025

Use the comparison tool below to compare the top Free API Testing tools on the market. You can filter results by user reviews, pricing, features, platform, region, support options, integrations, and more.

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    Loadmill Reviews
    Generate automated API tests directly from actual user sessions with Loadmill, which assists organizations in streamlining their development pipeline, enhancing speed, and automating manual testing through the replication of genuine user activity. By replaying thousands of user flow tests, you can effectively eliminate regression issues, shortening the duration of your regression cycles while allowing your team to concentrate on essential tasks. Minimize expenses related to inefficient testing practices and maintenance, as Loadmill automatically creates regression tests derived from real user interactions. This lets your team move swiftly and remain focused on priorities that matter most. By automating the entire quality assurance process through the recreation of authentic user behavior, Loadmill can be seamlessly integrated into your continuous delivery pipeline, enabling faster shipping of updates. Leveraging real traffic from websites globally, Loadmill tests your server's performance quickly, allowing you to launch tests within seconds and identify bottlenecks before they affect production. With a truly distributed system, you can utilize an unlimited number of unique IP addresses and locations for each test, while also having the capability to record and replay specific user scenarios at scale, ensuring comprehensive coverage and reliability in your testing efforts.
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    PFLB Reviews

    PFLB

    PFLB

    $50/month
    PFLB specializes exclusively in performance testing. We help companies identify and resolve performance bottlenecks, such as slow database queries or API calls that are not performing well. We are the company of choice for clients who need performance testing across a wide range of technologies, such as web and mobile applications and core banking systems. We offer a wide range of solutions for JMeter, LoadRunner and other environments. PFLB is a load testing platform that allows companies to perform efficient and scalable performance test. PFLB is a global leader in performance testing with over 15 years' experience.
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    KeyRunner Reviews

    KeyRunner

    Launchiam

    $39/month/user
    A Comprehensive Solution for Developing, Testing, and Securing APIs. Revolutionize the way you create, evaluate, and oversee your APIs. Work collaboratively, execute tests locally, and safeguard sensitive information throughout the entire process. Instant Access, No Signup Required Begin using our platform immediately—eliminate the hassle of cumbersome registration or sign-in procedures. Integrations with VS Code & Desktop Applications Utilize our VS Code extension and desktop applications to ensure a smooth integration with your preferred working environment. Secure Local Storage & Execution Maintain the safety of your data through local storage and execution, which guarantees that confidential information remains on your device. Unlimited Collection Testing Effortlessly test and manage an infinite number of API collections, allowing for seamless scalability across all your initiatives. Create Mock Servers Enhance your development process by setting up mock servers that facilitate rapid testing and simulation of API responses. User-Friendly Testing & Playground Make testing easier with our intuitive interface—explore APIs without the need for any coding. Our advanced enterprise capabilities elevate your API management experience. Reach out to us for more information and to see how we can assist you further!
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    Requestly Reviews

    Requestly

    RQ Labs, Inc.

    $0
    The Requestly API Client provides an array of features designed to assist in the effective design, management, and testing of APIs. This innovative tool serves as a valuable asset for both developers and quality assurance professionals, thanks to its unique combination of functionalities. 1. API Design: Requestly enhances the API design process by enabling users to create specific API requests while defining HTTP methods, headers, query parameters, and request bodies with ease. 2. API Request Execution: Central to API testing is the ability to send API requests, with detailed views available for responses that encompass status codes, headers, and payload content. 3. Organizing API Collections: By utilizing collections, users can neatly group related API requests, improving organization and facilitating teamwork. 4. Use of Variables: Requestly streamlines the API management and testing processes by allowing users to substitute hardcoded values with placeholders, including Collection, Environment, and Global Variables. 5. Scripting Capabilities: The inclusion of pre- and post-scripts enables users to apply logic or make modifications to requests prior to sending them, as well as to process responses and adjust variables for future API calls. This comprehensive suite of tools makes Requestly an essential resource for anyone involved in API development and testing.
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    Runscope Reviews
    An API Monitoring test using Runscope consists of one or multiple HTTP requests executed in a sequence to assess the availability, speed, and accuracy of an API. During each phase of the test, you can set up Assertions to check the response data and utilize Variables to retrieve information for later requests. A test is considered successful if all assertions are satisfied, whereas it will fail if any assertion does not hold true or if an error occurs, such as issues with the network connection. It’s crucial that your clients are not the ones informing you about service outages or malfunctions. Runscope integrates with your existing notification platforms like PagerDuty, Slack, HipChat, email, webhooks, and others. By actively monitoring your service performance, you can swiftly identify and troubleshoot API issues. Utilize the API Dashboard and daily API Performance Report to stay ahead of sporadic failures before they escalate into significant concerns. Ensure that your API calls' structure and content align with your expectations, as powerful and flexible assertions provide you with comprehensive control over the testing process. With these tools in hand, you can maintain a robust and reliable API experience for your users.
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    ApiScout Reviews

    ApiScout

    ApiScout

    $5 per month
    ApiScout serves as a comprehensive platform for the creation, evaluation, and documentation of REST APIs, boasting impressive speed without the need for waiting, restarts, or loading indicators, and is optimized for all Mac devices. You can easily craft requests and analyze responses with its user-friendly interface. As an indispensable HTTP Client tool, ApiScout streamlines the API development process, allowing you to categorize requests into organized folders for better management. Furthermore, it supports the use of dynamic values, enabling you to incorporate calculations, previous response data, environment variables, and computed hashes into your requests seamlessly. Environment variables are particularly useful for clustering related values, making it easy to switch between different user accounts or servers. By defining reusable variables such as tokens, base URLs, or credentials, you can enhance your workflow, ensuring a smooth transition between development and production environments. This level of organization and efficiency makes ApiScout an essential tool for any developer working with APIs.
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    ContextQA Reviews
    ContextQA is an innovative solution designed to help organizations boost their automation testing capabilities, improve software quality, accelerate product release timelines, and significantly reduce costs associated with maintaining software standards by leveraging AI-powered SaaS technology. By transforming manual test cases and user stories into automated tests, AI agents streamline the testing process. Additionally, ContextQA gathers evidence and conducts root-cause analysis when bugs are detected. It identifies key user journeys and highlights deficiencies in the software testing framework. With comprehensive end-to-end testing, including contract testing, there is no longer a necessity for distinct tools for front-end and back-end testing. It allows for the identification of issues, performance improvements, and ensures smooth user interactions across various browsers, mobile devices, and operating systems. Furthermore, ContextQA makes it easier to integrate test cases with minimal effort, facilitating a swift increase in automation coverage for your products and services while ultimately enhancing productivity and efficiency.
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    Stellar Reviews
    Accelerate your testing workflows using Stellar’s low-code automation platform. Boost productivity, reduce mistakes, and attain more intelligent software testing through seamless solutions for UI, API, mobile, performance, and accessibility assessments. Enable your team to conduct more tests while experiencing less stress, thanks to easy integration and sophisticated analytics tools. With Stellar, you can transform your testing approach and unlock new levels of efficiency.
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    JMeter Reviews

    JMeter

    Apache Software Foundation

    Apache JMeter™ is an open source tool developed in pure Java, intended for conducting load tests to assess functional behavior and performance metrics. Initially created for web application testing, its capabilities have grown to encompass various testing functions. This versatile software can evaluate the performance of both static and dynamic resources, including web applications that are dynamic in nature. By simulating substantial loads on a single server or a network of servers, it allows users to examine the system's resilience and analyze its performance across different types of loads. As a result, Apache JMeter has become an essential tool for developers and testers seeking to ensure optimal performance and reliability in their applications.