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

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.

Designed for optimal performance and effective resource management, KrakenD is capable of handling an impressive 70,000 requests per second with just a single instance. Its stateless architecture promotes effortless scalability, eliminating the challenges associated with database maintenance or node synchronization. When it comes to features, KrakenD excels as a versatile solution. It supports a variety of protocols and API specifications, providing detailed access control, data transformation, and caching options. An exceptional aspect of its functionality is the Backend For Frontend pattern, which harmonizes multiple API requests into a unified response, thereby enhancing the client experience. On the security side, KrakenD adheres to OWASP standards and is agnostic to data types, facilitating compliance with various regulations. Its user-friendly nature is bolstered by a declarative configuration and seamless integration with third-party tools. Furthermore, with its community-driven open-source edition and clear pricing structure, KrakenD stands out as the preferred API Gateway for enterprises that prioritize both performance and scalability without compromise, making it a vital asset in today's digital landscape.

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.

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.

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.

Tyk is a prominent Open Source API Gateway and Management Platform, recognized for its leadership in the realm of Open Source solutions. It encompasses a range of components, including an API gateway, an analytics portal, a dashboard, and a dedicated developer portal. With support for protocols such as REST, GraphQL, TCP, and gRPC, Tyk empowers numerous forward-thinking organizations, processing billions of transactions seamlessly. Additionally, Tyk offers flexible deployment options, allowing users to choose between self-managed on-premises installations, hybrid setups, or a fully SaaS solution to best meet their needs. This versatility makes Tyk an appealing choice for diverse operational environments.

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.

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.

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.

Eggplant enables organizations to craft exceptional digital experiences that captivate users. We assist businesses in tracking, evaluating, and enhancing their customer interactions effectively. Companies globally leverage Eggplant to surpass their rivals, boost efficiency, and provide outstanding customer satisfaction. So, how does Eggplant achieve this? It significantly elevates the quality, speed, and functionality of software applications across a variety of interfaces and platforms, including mobile devices, IoT, and desktops, all within agile, DevOps, and pioneering application and data environments. Additionally, Eggplant’s comprehensive approach ensures that organizations can adapt swiftly to changing market demands while maintaining high standards of performance.

Appvance IQ (AIQ) significantly enhances productivity and reduces costs associated with test creation and execution. It provides both AI-powered fully automated tests and third-generation codeless scripting options for developing tests. The scripts generated undergo execution via data-driven functional and performance testing, including app-pen and API assessments for both web and mobile applications. With AIQ's self-healing technology, you can achieve comprehensive code coverage using only 10% of the effort that traditional testing methods demand. Moreover, AIQ identifies critical bugs automatically, requiring very little intervention. There is no need for programming, scripting, logs, or recording, simplifying the overall testing process. Additionally, AIQ readily integrates with your current DevOps frameworks and tools, streamlining your workflow even further. This seamless compatibility enhances the efficiency of your testing strategy and overall project management.

TestEngine is an exceptionally effective platform tailored for the large-scale automated execution of SoapUI and ReadyAPI tests. It provides flexible deployment methods that allow for installation in diverse environments, such as cloud services or on-premises systems, utilizing Docker, virtual machines, or operating systems like Mac, Linux, and Windows, thus supporting both centralized and distributed execution strategies. By harnessing TestEngine, teams can dramatically accelerate their delivery pipelines through the simultaneous execution of tests. This tool can proficiently manage extensive test suites alongside quicker, impromptu test cases, all while necessitating minimal infrastructure maintenance. TestEngine adeptly handles the queuing of test requests, even during times of peak demand, ensuring that results are promptly returned to users on distributed clients while preserving data for future reference. The critical role of comprehensive testing is underscored, as it is vital for the successful delivery and upkeep of high-quality applications and services. Moreover, with TestEngine, teams can refine their testing workflows and simplify execution processes, circumventing the typical hurdles associated with intricate environments, which ultimately fosters greater productivity and efficiency in software development. This positions TestEngine as an indispensable asset in modern testing landscapes.

PFLB focuses solely on performance testing, assisting businesses in pinpointing and addressing performance issues like sluggish database queries or underperforming API calls. As the preferred partner for clients needing performance evaluation across diverse technologies—including web and mobile applications as well as core banking systems—we deliver tailored solutions. Our offerings encompass a variety of tools for JMeter, LoadRunner, and other testing environments. PFLB serves as an effective load testing platform, enabling organizations to execute performance tests that are both efficient and scalable. With more than 15 years of expertise, PFLB has established itself as a leading authority in the field of performance testing on a global scale. Our commitment to innovation and excellence ensures that we continuously meet the evolving needs of our clients.

An All-Inclusive Approach to API Development, Testing, and Security. Transform how you design, assess, and manage your APIs in a cohesive manner. Collaborate with your team, run tests on your local machine, and protect sensitive data throughout every stage of your project. Immediate Access, No Registration Needed Start utilizing our platform right away—remove the barriers of lengthy sign-up or login processes. Seamless Integration with VS Code & Desktop Tools Leverage our VS Code extension and desktop applications for effortless compatibility with your existing workflow. Protected Local Storage & Execution Ensure your data's security through local storage and execution, guaranteeing that private information stays on your device. Unlimited Testing of API Collections Easily test and oversee countless API collections, providing seamless scalability for all your projects. Create Mock Servers Streamline your development workflow by establishing mock servers that allow for quick testing and simulation of API responses. Intuitive Testing Environment & Playground Simplify the testing process with our user-friendly interface—discover APIs without needing any programming skills. Our sophisticated enterprise features enhance the overall management of your APIs, giving you more control and insight. Contact us today to learn more about how we can support your API journey!

The Requestly API Client is equipped with a diverse set of features aimed at enhancing the design, management, and testing of APIs effectively. This cutting-edge tool proves to be an invaluable resource for developers and quality assurance experts alike, owing to its distinctive blend of functionalities. 1. API Design: With Requestly, users can significantly improve the API design workflow by crafting precise API requests while effortlessly specifying HTTP methods, headers, query parameters, and request bodies. 2. API Request Execution: At the heart of API testing lies the functionality to dispatch API requests, with comprehensive views available for responses that detail status codes, headers, and payload data. 3. Organizing API Collections: Users can enhance organization and teamwork by leveraging collections to neatly categorize related API requests. 4. Use of Variables: Requestly simplifies API management and testing by enabling users to replace hardcoded values with placeholders, which include Collection, Environment, and Global Variables. 5. Scripting Capabilities: The tool’s pre- and post-script functionalities allow users to implement logic or make adjustments to requests before they are sent, as well as to handle responses and modify variables for subsequent API interactions. In conclusion, this all-encompassing suite of tools makes Requestly a crucial asset for anyone engaged in the realms of API development and testing, ensuring that processes are both streamlined and efficient. Its user-friendly interface further enhances the overall experience, making it accessible to individuals with varying levels of expertise.

HTTPie is transforming the landscape of API interaction by providing a simple and intuitive experience for developers who are shaping the technology of today. With features like AI support, neatly categorized HTTP methods in tabs, a handy context menu for libraries, and compatibility with cURL input mode, it merges the simplicity of the terminal version with a sleek graphical interface. This open-source tool for API testing is tailored for forward-thinking individuals, gaining the confidence of developers globally for their testing requirements. Among our diverse user base are engineers from top tech firms who are pivotal in driving substantial advancements in the industry. Our goal is to simplify and enrich the API experience for all creators involved in tools, applications, and cutting-edge technologies. We firmly believe in the potential of APIs to enact positive change in the world. Users can engage seamlessly with multiple APIs while taking advantage of AI-enhanced features. Furthermore, our platform promotes effective organization through the use of spaces, collections, and tabs, allowing users to customize requests utilizing variables and environments. With beneficial attributes like auto-save and real-time synchronization across devices, developers can prepare and refine their requests without needing to send them right away, which nurtures a more productive and straightforward workflow. In addition, this flexibility encourages experimentation and innovation, paving the way for the next generation of technological solutions.