List of the Top 25 API Testing Tools for Freelancers 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.

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.

Simplified Testing Without Code Empower every member of your team, not just developers, to create and manage automated tests effortlessly. Address your testing needs efficiently, achieving comprehensive test coverage in mere days instead of several months. Our tests designed in natural language are highly resilient to changes in the codebase, and our AI swiftly fixes any test failures that may arise. Continuous Testing is essential for Agile and DevOps practices, allowing you to deploy features to production within the same day. Boozang provides various testing methods, including: - A Codeless Record/Replay interface - BDD with Cucumber - API testing capabilities - Model-based testing - Testing for HTML Canvas The following features streamline your testing process: - Debugging directly within your browser console - Screenshots pinpointing where tests fail - Seamless integration with any CI server - Unlimited parallel testing to enhance speed - Comprehensive root-cause analysis reports - Trend reports to monitor failures and performance over time - Integration with test management tools like Xray and Jira, making collaboration easier for your team.

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.

Global App Testing (GAT) offers technology teams the opportunity to conduct tests across more than 189 countries, utilizing a network of over 60,000 skilled testers who operate on authentic devices and within genuine environments. By utilizing the GAT platform, you can enhance your testing procedures and boost the quality and speed of your releases while simultaneously improving budget efficiency, as the platform is designed to integrate smoothly with your current DevOps or CI/CD systems. Whether your needs involve continuous QA support or managing fluctuations in your release schedules, GAT’s integration-centric strategy allows you to oversee your entire testing process, from initiating tests to analyzing results, all without departing from your usual tools like Github, Jira, or Testrail. Our comprehensive platform supports both unscripted exploratory testing and scripted functional test case execution, seamlessly integrating into your CI/CD and SDLC workflows, thus aligning perfectly with your automation testing solutions. Results are delivered in real time, with initial feedback available in as little as 15 minutes, followed by a detailed bug report within a few hours, facilitating rapid responses to critical issues and edge cases, which ultimately leads to a more efficient development cycle. This approach not only streamlines your testing efforts but also aligns with your overall project goals, ensuring that you remain agile in a fast-paced technological landscape.

It's clear that enhancing your testing efforts could help identify bugs sooner, yet effective QA testing often demands significant time, effort, and resources. With MuukTest, engineering teams can achieve up to 95% coverage of end-to-end tests in a mere three months. Our team of QA specialists is dedicated to creating, overseeing, maintaining, and updating E2E tests on the MuukTest Platform for your web, API, and mobile applications with unparalleled speed. After reaching 100% regression coverage within just eight weeks, we initiate exploratory and negative testing to discover bugs and further elevate your testing coverage. By managing your testing frameworks, scripts, libraries, and maintenance, we significantly reduce the time you spend on development. Additionally, we take a proactive approach to identify flaky tests and false results, ensuring that your testing process remains accurate. Consistently conducting early and frequent tests enables you to catch errors during the initial phases of the development lifecycle, thus minimizing the burden of technical debt in the future. By streamlining your testing processes, you can improve overall product quality and enhance team productivity.

Testim offers a rapid method for developing robust end-to-end test cases, accommodating both codeless and coded options. It empowers users to design stable, codeless tests utilizing advanced AI capabilities. Additionally, you can export your tests into code format, with access to Testim's JavaScript API for seamless integration with your development environment. This functionality enables you to easily debug, adjust, or refactor your tests as needed. To ensure consistency, you can store your tests in a version control system, allowing for execution with each code commit. Each month, millions of users, including notable companies like NetApp, Wix, and JFrog, rely on Testim for their testing needs. For further information, please visit our website to explore all that we offer.

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.

With Kinective Bridge™ (previously known as OmniConnect), you can tap into the most extensive collection of integrated fintech solutions, boasting over 80 integrations that cover 99% of core systems in the United States. This platform enables you to effortlessly link your core with top-tier fintech providers to drive digital transformation, enhance operational efficiency, and elevate customer satisfaction. • A ready-to-go solution that ensures secure, all-encompassing, and well-supported connectivity • Enable innovation at your own pace while scaling growth without the requirement for extensive development resources • Reduce manual workflows and minimize the risk of human error • Utilize the most extensive library of integrated fintech solutions, giving you the freedom to select any system, technology, or provider While transformation may seem appealing in theory, implementing it poses challenges, particularly when dealing with outdated technology and legacy systems. Transitioning between cores or expending significant in-house development time to integrate various systems can often become a lengthy and cumbersome endeavor, requiring careful planning and execution to ensure success.

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.

Tuskr is an intuitive and robust test management software that simplifies the testing process. This tool enables users to handle test cases, execute test runs, and enhance their testing efficiency. Additionally, it allows seamless integration with existing bug tracking and time management applications. A complimentary 30-day trial featuring sample data is available for those looking to evaluate its capabilities, alongside a generous free plan for users who want to continue using it. With such offerings, Tuskr makes testing management accessible to teams of all sizes.

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.

API Tester is a versatile mobile application available for both iOS and Android platforms that facilitates the testing and utilization of APIs. This entirely free tool boasts a streamlined design while offering extensive functionality, enabling users to tackle complex tasks efficiently on smaller screens. - It supports testing for various API types including REST, GraphQL, WebSocket, SOAP, JSON RPC, XML, HTTP, and HTTPS. - Users can execute all HTTP request methods such as GET, POST, PUT, PATCH, DELETE, and HEAD. - The app allows API calls with diverse request data encodings and transfer methods, including query parameters, FormData, and raw data; advanced features permit users to bypass TLS, turn off redirects, and modify timeout settings. - Requests or collections can be imported effortlessly via cURL, links, or files from devices, with compatibility for Swagger, OpenAPI, Postman, and YAML collections. - Sharing requests is made easy with deep links and cURL commands for quick distribution. - It includes a robust GraphQL editor that provides a comprehensive experience featuring a body editor for Queries, Mutations, Subscriptions, and syntax highlighting, as well as a variables editor and documentation access. - Additionally, a WebSocket testing tool is integrated to manage connections and message exchanges through WS or WSS protocols. This means you can seamlessly engage with the APIs you need while on the go, leaving your laptop behind and enhancing your productivity wherever you are!

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.

Xano provides a comprehensive, managed infrastructure designed to support your backend needs with scalability. It allows you to rapidly establish the necessary business logic without needing to write any code, or alternatively, you can utilize our pre-designed templates for a swift launch that maintains both security and scalability. Creating custom API endpoints only requires a single line of code, streamlining the development process. With our ready-made CRUD functions, Marketplace extensions, and templates, you can significantly reduce your time to market. Your API comes prepped for immediate use, enabling you to connect it to any frontend while you focus on refining your business logic. Additionally, Swagger automatically generates documentation for seamless frontend integration. Xano incorporates PostgreSQL, offering the advantages of a relational database along with the capabilities required for big data, akin to a NoSQL solution. Enhancing your backend is straightforward, as you can implement new features with just a few clicks, or leverage existing templates and extensions to expedite your project. This flexibility ensures that developers can adapt quickly to changing requirements while maximizing efficiency.

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.

An advanced functional testing tool designed to expedite test automation for web, mobile, and enterprise applications. This intelligent automation leverages AI-driven features to enhance testing efficiency across various platforms, including desktop, mobile, mainframe, and hybrid environments. Serving as a unified testing solution, it streamlines and speeds up the testing processes for over 200 enterprise applications, technologies, and environments. By utilizing AI, this intelligent testing automation minimizes the time and resources needed to develop and maintain functional tests while simultaneously boosting test coverage and robustness. It is essential to test both the front-end user interface and the back-end service components to ensure comprehensive coverage across UI and API. With capabilities for parallel testing, cross-browser support, and cloud-based operation, this tool enables rapid testing execution, allowing teams to achieve faster results and improve overall efficiency. Such a robust testing solution is crucial for organizations aiming to enhance their development lifecycle and deliver high-quality software.

Apidog provides an all-encompassing array of tools aimed at optimizing the complete API lifecycle, allowing research and development teams to implement best practices centered around API design. Featuring a powerful visual editor, the platform enables users to efficiently design and troubleshoot their APIs. It improves user experience with support for JSON Schema, which makes describing and debugging APIs more straightforward. Apidog automates key components of the API lifecycle, such as generating tests from API specifications, performing visual assertions, validating responses, and integrating seamlessly with continuous integration and continuous deployment (CI/CD) processes. Moreover, it supports the creation of visually appealing API documentation that can be either shared securely among teams or published on a custom domain. With its local and cloud-based mock engine, Apidog generates realistic mock data that corresponds to field names and specifications, eliminating the necessity for writing scripts. The suite of high-quality tools allows your team to collaborate effectively while reducing repetitive tasks. You can easily describe your API during testing and generate JSON or XML schemas with a single click. Additionally, creating test cases from APIs, adding assertions visually, and developing complex test scenarios that include branches and iterations becomes a straightforward task. By utilizing Apidog, teams can significantly boost their productivity and enhance collaboration throughout the entire development lifecycle, leading to more innovative solutions and improved project outcomes.

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.