Best API Testing Tools for Linux

KrakenD is a high-performance API Gateway optimized for resource efficiency, capable of managing 70,000 requests per second on a single instance. The stateless architecture allows for straightforward, linear scalability, eliminating the need for complex coordination or database maintenance. It supports various protocols and API specifications, with features like fine-grained access controls, data transformation, and caching. Unique to KrakenD is its ability to aggregate multiple API responses into one, streamlining client-side operations. Security-wise, KrakenD aligns with OWASP standards and doesn't store data, making compliance simpler. It offers a declarative configuration and integrates with third-party logging and metrics tools. With transparent pricing and an open-source option, KrakenD is a comprehensive API Gateway solution for organizations prioritizing performance and scalability.

"Parasoft delivers an AI‑powered software testing platform that helps organizations continuously release high‑quality software. Our solutions support embedded and enterprise teams by integrating code analysis, testing, virtualization, and coverage into the delivery pipeline to improve security, reliability, and compliance while reducing cost and effort. Parasoft C/C++test provides static analysis, unit testing, code coverage, and requirements traceability for C and C++ applications. It integrates with Eclipse and Visual Studio, supports CI/CD automation, and is TÜV‑certified for safety‑ and security‑critical systems. Parasoft C/C++test CT is a scalable, compliance‑ready solution for C and C++ teams. It integrates into CI/CD workflows, supports open‑source unit testing frameworks, containers, VS Code, Bazel build systems, eliminates IDE dependencies, and is TÜV‑certified for safety‑ and security‑critical development."

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.

Testsigma is an AI-native quality intelligence platform that gives QA and engineering leaders the evidence to answer that question. It compares test coverage against what is actually being built and produces a release confidence score with known confidence bounds. When gaps are found, Testsigma closes the loop: AI agents generate the missing tests, run them with self-healing, diagnose failures, and file complete bug reports. For teams that need comprehensive test execution, Testsigma supports web, mobile, API, and Salesforce testing with cross-browser and cross-device execution at scale on real devices. Testsigma serves mid-market and enterprise engineering teams across financial services, insurance, healthcare, manufacturing, retail, public sector, and technology. Recognized by Gartner in the Market Guide for AI-Augmented Enterprise Application Testing Tools and by Forrester in the Autonomous Testing Platforms Landscape.

T-Plan Robot automates scripted user actions for Test Automation or Robotic Process Automation (RPA) on Mac, Windows Linux & Mobile. T-Plan develops and sells two main toolsets. 1) Test Automation and 2) Robotic Process Automation (RPA). T-Plan Robot is a highly flexible, easy to use, image-based black box GUI automation tool that creates robust automated scripts and exercises applications in the same way as would an end-user. T-Plan Robot is platform-independent (Java) and runs on, and automates all major systems such as Windows, Mac, Linux and Unix plus mobile platforms. We believe we have a solution for any environment. GUI automation interacts with your business sponsor and development teams throughout the whole project lifecycle. Working intuitively at the screen level business analysts can help testers drive testable paths through the application, whilst at the same time combining with the development team to define repeatable actions to test code in continuous development.

Tyk is a leading Open Source API Gateway and Management Platform, featuring an API gateway, analytics, developer portal and dashboard. We power billions of transactions for thousands of innovative organisations. By making our capabilities easily accessible to developers, we make it fast, simple and low-risk for big enterprises to manage their APIs, adopt microservices and adopt GraphQL. Whether self-managed, cloud or a hybrid, our unique architecture and capabilities enable large, complex, global organisations to quickly deliver highly secure, highly regulated API-first applications and products that span multiple clouds and geographies.

ZAPTEST is a leading Free and Enterprise software test automation and RPA tool. Offerings include Computer Vision technology that allows for Cross-Platform digital interface automation for UI, API, Load testing, and RPA in a seamless process. Combine that with our 1SCRIPT methodology, seamless automation, parallel execution, and unlimited licenses– you get an efficient testing suite that generates up to 10X ROI. We promise that if you can perform a procedure via any digital interface (live application or mockup) manually, ZAPTEST can automate this procedure As-Is! With ZAPTEST’s Enterprise Solution subscription program, you receive unlimited licenses across the entire organization. Regardless of whether your automation needs increase, your cost remains fixed. FARM allows ZAPTEST users to manage all of their devices so you can remotely control cross-environments and projects from any location. ZAPTEST uses many practical applications to enhance its software testing software capabilities

Capture all HTTP(S) traffic between your computer and the Internet with Telerik Fiddler HTTP(S) proxy. Inspect traffic, set breakpoints, and fiddle with requests & responses. Fiddler Everywhere is a web debugging proxy for macOS, Windows, and Linux. Capture, inspect, monitor all HTTP(S) traffic between your computer and the Internet, mock requests, and diagnose network issues. Fiddler Everywhere can be used for any browser, application, process. Debug traffic from macOS, Windows, or Linux systems and iOS or Android mobile devices. Ensure the proper cookies, headers, and cache directives are transferred between the client and server. Supports any framework, including .NET, Java, Ruby, etc. Mock or modify requests and responses on any website. It’s a quick and easy way to change the request and responses to test websites without changing code. Use Fiddler Everywhere to log all HTTP/S traffic between your computer and the Internet.

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

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.