Best Free API Testing Tools of 2025 - Page 3

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.

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!

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.

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.

Create an API in just half an hour and share it with your colleagues or clients, allowing them to explore the API mock without any coding required. By enabling them to interact with the mock, you can gather valuable feedback and refine your design before committing to actual coding, ensuring that the end product truly meets the needs of your developers. Think of it as the DNA of your API—robust, open-source, and designed with developers in mind. It seamlessly combines the simplicity of Markdown with the capabilities of automated mock servers, testing, validation, proxies, and code samples in various programming languages. Often, it can be challenging to predict how an API will be utilized until you engage with it in a coding context. Just as wireframes are essential for UI design, a server mock serves a similar purpose for API development, allowing for rapid prototyping before any code is written. With just two clicks, you can connect Apiary to any repository you choose, giving you the flexibility to decide whether to keep your API Blueprint private or to open it to public collaboration. Every time you commit changes, we ensure that your API documentation stays updated, and we automatically synchronize commits to your repository whenever you make edits at Apiary. This creates a beneficial feedback loop that enhances the quality and functionality of your API over time, streamlining the development process.

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.

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.

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.

ApiScout provides a one-stop shop for testing, building, and describing Rest Apis. It is extremely fast. There is no waiting or restarting. No spinners. Fast on all Mac devices. Make requests and inspect the responses ApiScout will be the only HTTP Client tool that you need to build, test, and describe your APIs. You can organize your requests into folders Dynamic values Use dynamically calculated values, previous responses, environment variables and computed hashes. In every part of your request. Environment variables You can group similar sets of values together using environments. It is very useful for switching user accounts, servers, and other tasks. Define variables like tokens, server base URLs, or credentials and re-use them globally for a seamless development/production workflow.