List of the Top 25 API Testing Tools for Windows in 2025

Software designed for ongoing performance testing facilitates the automation of API load and application evaluations. In the case of intricate applications, users can create performance tests without needing to write code. Automated pipelines can be utilized to script these performance tests specifically for APIs. Users have the ability to design, manage, and execute performance tests using coding practices. Afterward, the results can be assessed within continuous integration pipelines, leveraging pre-packaged plugins for CI/CD tools or through the NeoLoad API. The graphical user interface enables quick creation of test scripts tailored for large, complex applications, effectively eliminating the time-consuming process of manually coding new or revised tests. Service Level Agreements (SLAs) can be established based on built-in monitoring metrics, enabling users to apply stress to the application and align SLAs with server-level statistics for performance comparison. Furthermore, the automation of pass/fail triggers utilizing SLAs aids in identifying issues effectively and contributes to root cause analysis. With automatic updates for test scripts, maintaining these scripts becomes much simpler, allowing users to update only the impacted sections while reusing the remaining parts. This streamlined approach not only enhances efficiency but also ensures that tests remain relevant and effective over time.

Streamline the creation of production-ready APIs with ease. With advanced features like AI-driven code generation, quick mocking, and on-demand temporary testing setups, Blackbird offers a comprehensive solution. Utilizing Blackbird's unique technology and user-friendly tools, you can quickly define, mock, and generate boilerplate code. Collaborate with your team to validate specifications, execute tests in a real-time environment, and troubleshoot issues seamlessly within the Blackbird platform. This empowers you to confidently launch your API. You can manage your testing environment on your own terms, whether on your local device or through the dedicated Blackbird Development Environment, which is always accessible through your account without incurring any cloud expenses. In mere seconds, OpenAPI-compliant specifications are generated, allowing you to dive into coding without the hassle of design delays. Furthermore, dynamic and easily shareable mocking features eliminate the need for tedious manual coding or upkeep. Validate your process and proceed with confidence. Enjoy a more efficient workflow that accelerates your development cycle and enhances collaboration across teams.

Parasoft aims to deliver automated testing tools and knowledge that enable companies to accelerate the launch of secure and dependable software. Parasoft C/C++test serves as a comprehensive test automation platform for C and C++, offering capabilities for static analysis, unit testing, and structural code coverage, thereby assisting organizations in meeting stringent industry standards for functional safety and security in embedded software applications. This robust solution not only enhances code quality but also streamlines the development process, ensuring that software is both effective and compliant with necessary regulations.

Testsigma serves as a low-code automation platform designed for Agile teams, enabling seamless collaboration among SDETs, manual testers, subject matter experts, and quality assurance professionals in planning, developing, executing, analyzing, debugging, and reporting their automated tests for websites, native Android and iOS applications, and APIs. This versatile tool is offered as both a fully managed cloud solution and a self-hosted open-source instance, known as Testsigma Community Edition. While the platform's architecture is based on Java, its automated testing capabilities remain code-agnostic, allowing teams to describe user actions in straightforward English using its built-in NLP Grammar or to create comprehensive test scripts through the Test Recorder. Additionally, Testsigma incorporates features such as visual testing, data-driven testing, two-factor authentication testing, and an AI component that resolves unstable elements and test steps, locates regression-affected scripts, and offers suggestions to address test failures. By consolidating numerous tools within the quality assurance process, Testsigma empowers teams to perform testing efficiently, continuously, and in a collaborative manner, ultimately streamlining their workflows and enhancing productivity.

TAST, or Test Automation System Tool, is a cloud-based solution designed to enhance test automation with a focus on the End User's experience. Its user-friendly graphical interface makes it easy to create automated test cases that span various technological platforms. TAST efficiently automates a wide range of testing types, including cross-browser testing, mobile testing, and database testing for systems like Oracle, PostgreSQL, MySQL, and Db2. Additionally, it covers file testing formats such as txt, pdf, Word, Excel, csv, and xml, as well as mainframe testing on AS400 and Host systems. API and interface testing are also supported, along with remote server testing capabilities. The diverse types of tests that can be automated with TAST include integration tests, functional tests, and system tests that encompass regressive, stress, load, and parallel testing. Furthermore, it offers support for acceptance testing and A/B testing, making it a comprehensive tool for businesses looking to streamline their testing processes. By leveraging TAST, organizations can significantly improve their testing efficiency and ensure better quality software delivery.

Postman is a collaborative platform tailored for API development, aimed at streamlining the process of creating APIs while promoting teamwork, which leads to the quick production of high-quality APIs. Its various features support every stage of API development, thereby enhancing collaboration and expediting the process of building superior APIs. Users have the ability to rapidly and easily send requests for REST, SOAP, and GraphQL APIs right within Postman, which optimizes their workflow significantly. Moreover, it offers the capability to automate manual testing, integrating these tests into your CI/CD pipeline to prevent potential issues when new code is deployed. The platform also enables effective communication regarding API behavior by allowing users to simulate endpoints and their responses without needing a backend server. Additionally, you can create and publish visually appealing, machine-readable documentation, making your API more user-friendly and accessible. Regular monitoring of performance and response times keeps you updated on the health of your API, allowing for proactive management. Furthermore, Postman encourages a shared environment for both the creation and consumption of APIs, fostering real-time collaboration among team members, which can lead to more innovative solutions. This combination of features not only enhances productivity but also helps teams work more cohesively towards developing robust APIs. Postman’s AI Agent Builder is a comprehensive tool that accelerates the creation, testing, and deployment of AI agents by providing easy integration with APIs and LLMs. It allows users to quickly turn APIs into agent-ready tools, test LLMs’ performance and costs, and compare responses to choose the best model. The no-code platform features a visual canvas that lets developers design and configure agent workflows with ease.

Cerberus Testing streamlines continuous testing with a low-code software solution that scales efficiently. This innovative tool removes the necessity for establishing an internal testing framework for an extended period. It empowers users to swiftly navigate through the entire testing lifecycle, encompassing test repository management, execution, and report generation. Furthermore, the platform fosters collaboration among teams, enabling them to work together from the creation of use cases to the execution of test cases across various browsers and devices. To facilitate large-scale test execution, users can tap into either their own or third-party robotic infrastructures, allowing a stronger focus on delivering business value. The solution also offers numerous integrations, including Bitbucket and Slack, to enhance implementation speed. As an open-source initiative, it benefits from the contributions of several major digital and retail companies, such as La Redoute, Decathlon, Adeo, and Norauto, ensuring its continuous improvement and relevance in the industry. This collaborative effort not only enriches the software's features but also builds a robust community around it.

QATTS is recognized as the premier provider of comprehensive cloud-based test automation solutions, catering to every phase of the testing process. Our commitment to ensuring the highest quality for your software applications and products is reflected in our customizable and readily available automation testing services. A dedicated team of seasoned QA analysts, automation test engineers, and IT professionals works in unison to deliver reliable services promptly and achieve immediate results. Proficient in both manual and automated testing, our QA experts leverage cutting-edge technologies across web, desktop, and mobile platforms, employing a wide range of testing tools. Our extensive knowledge of automation trends positions us as the go-to resource for all your test automation needs, encompassing RESTful and SOAP-based web services, along with IBM, Attachmate, and Hummingbird emulators. We remain steadfast in our dedication to evolving our services in response to the dynamic landscape of the industry and the specific requirements of our clients, ensuring that we stay ahead of the curve. This relentless pursuit of excellence solidifies our reputation as a leader in test automation solutions.

SoapUI testing tools, offered in both open source and commercial versions, make it easier to create, manage, and execute thorough tests for a variety of services including REST, SOAP, GraphQL APIs, JMS, JDBC, and more, thereby accelerating software delivery. For developers and testers looking to boost their skills in delivering REST and SOAP APIs, SoapUI Open Source is the most accessible and intuitive option for starting API testing. The advanced tools are crafted to optimize the validation of REST, SOAP, GraphQL, microservices, and other backend services, allowing teams to effortlessly incorporate API testing into their continuous delivery workflows. APIs, or Application Programming Interfaces, are essential for facilitating the connection and exchange of data and logic across different systems and applications, forming the backbone of modern software development. By implementing effective testing strategies for these APIs, organizations can significantly improve the efficiency of their overall testing process, leading to faster software delivery and enhanced quality outcomes. As teams adapt to the fast-changing technology environment, maintaining a competitive edge relies on the robustness of their testing frameworks. Ultimately, the emphasis on thorough API testing not only ensures product reliability but also fosters greater innovation and responsiveness in development practices.

T-Plan offers a Cross-Platform Test Automation Software that facilitates the execution of identical tests across various devices and platforms. T-Plan Robot serves as a highly adaptable and user-friendly, image-based black box GUI automation tool, generating robust automated scripts that interact with applications in a manner akin to end-users. This platform-independent solution, built on Java, can function across all major operating systems, including Windows, Mac, Linux, Unix, and various mobile platforms, ensuring we have a suitable option for any environment. Our virtual workforce solution is designed to be application and environment agnostic, allowing for seamless integration. Utilizing human-like GUI interactions, our Java Robot employs a non-intrusive, no-code, low-code development methodology to create efficient automation. Additionally, T-Plan's RPA leverages the same scripts to enable automation across Windows, Mac, and Linux, streamlining the automation development process. Notably, T-Plan Robot stands out as the only RPA tool available that seamlessly supports Mac, Linux, and Windows within a single application. This remarkable flexibility makes Robot the premier test automation tool on the market, offering consistent scripting capabilities for Mac, Windows, Linux, and mobile platforms alike, ensuring comprehensive coverage in any testing scenario.

Leverage the capabilities of Telerik Fiddler HTTP(S) proxy to capture all web traffic flowing between your computer and external websites, which enables you to examine that traffic, establish breakpoints, and adjust both requests and responses as needed. Fiddler Everywhere acts as a flexible web debugging proxy that is compatible with macOS, Windows, and Linux operating systems. It allows for the capturing, inspection, and monitoring of all HTTP(S) communications, making it easier to mock requests and address network issues. This tool can be utilized with any browser or application, providing the ability to debug traffic on macOS, Windows, Linux, and mobile devices running either iOS or Android. It ensures the proper exchange of essential cookies, headers, and caching settings between the client and server. Supporting a variety of frameworks including .NET, Java, and Ruby, Fiddler Everywhere equips you with the tools to efficiently mock or modify requests and responses on any website. This user-friendly approach enables testing of website functionality without necessitating any code changes. With Fiddler Everywhere, you can comprehensively log and analyze all HTTP/S traffic between your machine and the broader internet, thereby enhancing your debugging efficiency and allowing for more in-depth inspection of network interactions. Ultimately, this tool streamlines the process of identifying and resolving issues that might affect your web applications.

ZAPTEST stands out as a premier tool for both Free and Enterprise software test automation and Robotic Process Automation (RPA), leveraging advanced Computer Vision technology to facilitate seamless automation across various digital interfaces for both UI and API. Coupled with our unique 1SCRIPT methodology, ZAPTEST enables smooth automation, allows for parallel execution, and offers unlimited licenses, all of which contribute to a testing suite capable of delivering returns as high as 10X. The platform is versatile enough to automate any task achievable through any digital interface, whether it be a live application or a mockup. By choosing to collaborate with ZAPTEST, partners gain access to unmatched benefits that significantly enhance the software testing landscape and RPA methodologies. Our collaboration fosters innovation, allowing businesses to adopt cutting-edge automation solutions that elevate their efficiency and effectiveness. Moreover, ZAPTEST equips organizations with a cohesive automation platform designed to optimize both software testing and operational workflows, ensuring a streamlined approach to business processes. With our unlimited licensing model, scaling operations is not only simple but also enables businesses to evolve into agile and efficient entities in a competitive market.

Ambassador Edge Stack serves as a Kubernetes-native API Gateway that delivers ease of use, robust security, and the capability to scale for extensive Kubernetes environments globally. It simplifies the process of securing microservices by offering a comprehensive suite of security features, which encompass automatic TLS, authentication, and rate limiting, along with optional WAF integration. Additionally, it facilitates fine-grained access control, allowing for precise management of user permissions. This API Gateway functions as an ingress controller based on Kubernetes, and it accommodates an extensive array of protocols, such as gRPC, gRPC Web, and TLS termination, while also providing traffic management controls that help maintain resource availability and optimize performance. Overall, Ambassador Edge Stack is designed to meet the complex needs of modern cloud-native applications.

Alithya GoTest serves as an intuitive and efficient test hub that promotes teamwork and quick adoption, guaranteeing the dependability of digital solutions for businesses that demand uncompromising quality. Our user-friendly interface facilitates collaboration, execution, and resolution of tests while enabling communication across all team levels, ensuring that both test plans and results include the necessary details for effective analysis. Platform-agnostic in nature, Alithya GoTest enables seamless testing of desktop, web, and mobile applications, eliminating the need for extensive time and resources typically spent on building, maintaining, and integrating testing platforms into development workflows, thus empowering development teams to concentrate on adding value and enhancing quality. In contrast to traditional testing solutions, Alithya GoTest uniquely offers comprehensive end-to-end software testing through continuous testing within a DevOps framework. You can reach out to our exceptional bilingual support team or utilize our consulting, coaching, or online training resources to quickly familiarize yourself with the platform. Additionally, take advantage of our expanding catalog of pre-designed test suites tailored for major ERP platforms, such as Oracle Fusion Cloud, ensuring that software updates do not disrupt your existing solutions, thus enhancing overall operational resilience.

Tricentis Tosca enables automated continuous testing without requiring any coding, establishing itself as the premier platform in this field, which improves the testing experience via its no-code, script-free approach for thorough test automation. It accommodates an extensive array of over 160 technologies and enterprise applications, ensuring that test automation remains effective across diverse scenarios. The benefits of using Tricentis Tosca are numerous, including: - Quick feedback loops designed for Agile and DevOps settings - Drastic decreases in the time needed for regression testing, bringing it down to just minutes - Greater reusability and simpler maintenance of test assets - Increased clarity regarding potential business risks - Smooth integration with and enhancement of existing testing tools like HPE UFT, Selenium, and SoapUI, among others. By harnessing these features, organizations can optimize their testing workflows and elevate their overall quality assurance standards, ultimately leading to a more efficient software development lifecycle. This ensures that they remain competitive in rapidly evolving markets.

HttpMaster is a specialized tool designed for debugging and testing HTTP requests, particularly for web API applications and RESTful web services. Key features include the ability to create HttpMaster projects that encapsulate the full definition of request items. It offers a wide range of HTTP properties such as headers and URL encoding to ensure thorough testing. Users can leverage dynamic parameters to mimic different input scenarios or establish global API values for consistency. The tool also allows for response data validation using logical expressions, which enhances the accuracy of testing outcomes. Additionally, request chaining enables users to carry over data from one request to the next, facilitating more complex testing scenarios. HttpMaster supports extensive data upload options, including formats like 'multipart/form-data', which is crucial for testing file uploads. Furthermore, it includes a request data builder that allows users to customize the request body with optional parameters, enhancing flexibility. Users can monitor the execution of request items in detail and can organize requests into execution groups for batch processing. The tool also features a comprehensive review and management system for execution data, making it easier to analyze results. Ad-hoc execution is simplified with a basic request tool, and a command line interface is provided for automation purposes. Finally, HttpMaster supports generating PDF reports and executing cURL commands, making it a versatile choice for developers and testers alike.

Evaluate the functional, performance, and security dimensions of APIs, establishing Pass/Fail criteria to facilitate regression testing of API functionalities. These tests can be executed either on-demand or by utilizing command-line automation features. The tool is compatible with the latest OpenAPI specifications, allowing for the parsing of OpenAPI documents and the creation of test cases based on the defined operations. It accommodates various authentication methods, including SAML, OAuth, Basic Auth, Amazon Auth, PKI, and Kerberos. Users can establish behavior baselines and conduct regression tests to identify any disruptions or alterations in behavior. Additionally, it features capabilities for comparing JSON and XML outputs. The system can generate performance loads across numerous virtual clients to assess and ensure the performance criteria of the target APIs are met. Each request undergoes security and identity verification to simulate realistic inputs rather than replays. Moreover, it includes native support for AWSv4 signatures to facilitate authentication when testing Amazon AWS APIs, ensuring a comprehensive approach to API validation. This enables developers to reliably ensure that their APIs maintain functionality and performance standards as changes are made.

You have the option to utilize your preferred debugging software to address issues with your Kubernetes services on a local level. Telepresence, an open-source solution, facilitates the execution of a single service locally while maintaining a connection to a remote Kubernetes cluster. Originally created by Ambassador Labs, known for their open-source development tools like Ambassador and Forge, Telepresence encourages community participation through issue submissions, pull requests, and bug reporting. Engaging in our vibrant Slack community is a great way to ask questions or explore available paid support options. The development of Telepresence is ongoing, and by registering, you can stay informed about updates and announcements. This tool enables you to debug locally without the delays associated with building, pushing, or deploying containers. Additionally, it allows users to leverage their preferred local tools such as debuggers and integrated development environments (IDEs), while also supporting the execution of large-scale applications that may not be feasible to run locally. Furthermore, the ability to connect a local environment to a remote cluster significantly enhances the debugging process and overall development workflow.

ACCELQ is a cloud-native platform that utilizes AI to facilitate test automation and management without the need for coding. This comprehensive tool supports testing across various applications, including web, mobile, API, database, and packaged software. Its automation-first approach allows testing teams to operate efficiently, even without extensive technical skills or programming knowledge. By leveraging its innovative autonomics-based automation technology, ACCELQ helps companies increase productivity by threefold while also realizing cost reductions exceeding 70%. Furthermore, ACCELQ's recognition as a leader in The Forrester Wave™: Continuous Automation Testing Platforms for Q4 2022 highlights its exceptional standing in the market, making it a valuable asset for businesses looking to enhance their testing processes. The platform’s user-friendly interface and powerful capabilities further contribute to its appeal among organizations aiming for seamless automation.

Develop, troubleshoot, and assess APIs with a personal touch instead of an automated one. Finally, a workflow that you'll truly value. Presenting the Collaborative API Design Tool, a platform designed for crafting, validating, and managing OpenAPI specifications. This desktop client supports interactions with both REST and GraphQL, allowing you to effortlessly send requests and review responses. You can easily generate and organize your requests, configure environment variables, handle authentication, create code snippets, and much more. Delve into the details of responses—analyze the complete request timeline, encompassing status codes, body content, headers, cookies, and additional insights. Structure your project with workspaces, folders, and environments while utilizing a user-friendly drag-and-drop interface for requests, accompanied by simple data import and export functionalities. Within a unified collaborative API design editor, you can create, edit, lint, troubleshoot, preview, and oversee your OpenAPI specifications. Moreover, generate configurations for well-known API gateways like the Kong API Gateway and Kong for Kubernetes. Seamlessly synchronize your API designs with version control platforms such as GitHub or GitLab, and deploy straight to API gateways like Kong with a single click, greatly enhancing your development workflow. This tool not only boosts efficiency but also encourages teamwork among members in designing effective APIs, ultimately leading to a more innovative development environment.

Assessing and validating REST services in Java often presents more difficulties than with dynamic languages such as Ruby and Groovy. Nonetheless, REST Assured offers a user-friendly experience similar to those languages, which simplifies the process for developers working within the Java environment. By utilizing REST Assured, Java developers can effectively optimize their testing workflows, resulting in a notable boost in productivity. This tool not only mitigates complexity but also allows for a more efficient approach to service verification.

Test Mace is a modern and versatile cross-platform tool specifically designed for engaging with APIs and automating tests related to them. It empowers users to create requests and scenarios while offering features like variable management, authentication options, an autocomplete function, and syntax highlighting for ease of use. The interface is intuitive, making it easier to develop complex testing scenarios. With just a single click, users can run extensive regression tests, and the results from those tests can be conveniently saved in variables accessible from multiple nodes. Authorization tokens, response headers, and selected parts of response bodies can also be stored, which significantly boosts testing efficiency. Scenarios can be executed in various environmental contexts, facilitating effective management across development, staging, and production environments. Moreover, the tool includes built-in authentication methods that support the most common authentication types, simplifying the setup process for users. A key feature is the quick share functionality, which allows users to effortlessly share requests with team members by simply clicking a button to copy the URL of a specific node, thus fostering easy distribution among colleagues. This streamlined collaboration is vital for successful teamwork, ultimately enhancing productivity throughout the API testing process. Test Mace not only simplifies individual tasks but also cultivates a more cohesive working environment among teams.

Pynt is a cutting-edge API Security Testing Platform that unveils authenticated API vulnerabilities through simulated attacks. We assist numerous organizations, such as Telefonica, Sage, and Halodoc, in consistently monitoring, classifying, and preemptively addressing inadequately secured APIs before malicious hackers can exploit them. Leveraging a distinctive hacking methodology and an integrated shift-left approach, Pynt employs proprietary attack scenarios to identify genuine threats. In addition, it facilitates the discovery of APIs and provides recommendations for rectifying confirmed vulnerabilities. With the trust of thousands of businesses, Pynt plays a crucial role in safeguarding their applications. Many companies incorporate Pynt into their application security strategies to ensure robust protection against potential threats. This reliance on Pynt underscores its importance in the ever-evolving landscape of API security.

Sparrow offers a robust suite of tools aimed at optimizing the entire API lifecycle, assisting research and development teams in achieving superior outcomes in design-first API creation. Users can leverage cURL to effortlessly send API requests while utilizing vital methods like GET and POST. The platform enhances API interactions by effectively handling headers, data, and authentication processes. As an open-source collaborative platform for API development, Sparrow facilitates the efficient creation of exceptional APIs. With teamwork at the forefront, developers can enhance their methodologies early in the development timeline, leading to stronger APIs and quicker delivery times. Additionally, users benefit from smooth parallel testing across multiple environments, enabling them to collect crucial insights in real-time. Sparrow also provides powerful tools for securing and managing API data, along with self-hosting options that allow full control over testing environments. Moreover, developers can stay updated with the latest enhancements, insights, and resources offered by Sparrow, enriching their overall development experience. This dedication to ongoing improvement guarantees that developers have access to the most effective practices and cutting-edge innovations in the realm of API development, fostering a culture of continuous learning and adaptation.

Hoppscotch streamlines the creation and testing of APIs, allowing for faster product launches and enhanced efficiency. You can build APIs rapidly, perform instant tests, and automatically document and share your projects with ease. Whether you're working on initial prototypes or preparing for final production, everything you need for smooth API development is conveniently provided by Hoppscotch, eliminating the need to switch between multiple tabs. The platform allows for the establishment of dedicated workspaces tailored for your teams, offering customizable access controls as necessary. Real-time collaboration with colleagues is facilitated, leading to improved teamwork and productivity. Additionally, you have the option to deploy Hoppscotch on your own servers, providing you with greater flexibility and control. Organizing requests into collections or folders makes it easy to share with team members, while managing environment variables ensures consistency throughout your projects. You can also maintain a comprehensive record of your request history for quick reference. With the ability to modify headers, authenticate requests, generate random data, and explore an array of other features, thorough API testing is easily achievable, including writing assertions to verify responses. Hoppscotch accommodates over 30 languages, making it accessible in your preferred language. You can monitor all activities within your workspace, noting who performed actions and when, enhancing accountability. The integration of your existing SSO provider simplifies login processes, allowing for efficient user, workspace, and resource management. Moreover, the platform’s user-friendly interface ensures that both beginners and seasoned developers can navigate it without difficulty, making API development a more enjoyable experience overall. This comprehensive suite of features, combined with its adaptability, truly makes Hoppscotch a valuable tool for any development team.