Best Free API Testing Tools of 2025

Engineered for peak performance and efficient resource use, KrakenD can manage a staggering 70k requests per second on just one instance. Its stateless build ensures hassle-free scalability, sidelining complications like database upkeep or node synchronization. In terms of features, KrakenD is a jack-of-all-trades. It accommodates multiple protocols and API standards, offering granular access control, data shaping, and caching capabilities. A standout feature is its Backend For Frontend pattern, which consolidates various API calls into a single response, simplifying client interactions. On the security front, KrakenD is OWASP-compliant and data-agnostic, streamlining regulatory adherence. Operational ease comes via its declarative setup and robust third-party tool integration. With its open-source community edition and transparent pricing model, KrakenD is the go-to API Gateway for organizations that refuse to compromise on performance or scalability.

It works: Codeless testing Give your entire team the ability to create and maintain automated tests. Not just developers. Meet your testing demands fast. You can get full coverage of your tests in days and not months. Our natural-language tests are very resistant to code changes. Our AI will quickly repair any test failures. Continuous Testing is a key component of Agile/DevOps. Push features to production in the same day. Boozang supports the following test approaches: - Codeless Record/Replay interface - BDD / Cucumber - API testing - Model-based testing - HTML Canvas testing The following features makes your testing a breeze - In-browser console debugging - Screenshots to show where test fails - Integrate to any CI server - Test with unlimited parallel workers to speed up tests - Root-cause analysis reports - Trend reports to track failures and performance over time - Test management integration (Xray / Jira)

Testim is the fastest way to create resilient end-to-end test cases, whether they are codeless or coded. Testim allows you to create codeless, stable tests that leverage our AI. You also have the option to export your tests as code. Testim's JavaScript API is available to you and your IDE. This allows you to debug, modify, or refactor your tests. To keep them in sync, store them in your version control system. Run tests on every commit. Testim is used by millions of customers every month, including NetApp, Wix and JFrog. Find out more on our website.

Postman serves as a collaborative platform for developing APIs, designed to simplify the entire process of API creation and enhance teamwork, enabling the rapid development of superior APIs. The platform's features facilitate each phase of API construction, making it easier to collaborate and accelerate the creation of high-quality APIs. Users can quickly and effortlessly send requests for REST, SOAP, and GraphQL directly within Postman, optimizing their workflow. Additionally, it allows for the automation of manual tests, seamlessly integrating them into your CI/CD pipeline to safeguard against potential issues when code changes are deployed to production. API behavior can be communicated effectively by simulating endpoints and their respective responses without the need for a backend server setup. You can also generate and publish visually appealing, machine-readable documentation, which helps in making your API more accessible for users. Regular performance and response time checks ensure you stay informed about your API's health, allowing for proactive management. Lastly, Postman fosters a shared environment for API creation and consumption, enabling real-time collaboration among team members.

Cerberus Testing automates continuous testing at scale with low-code software. The solution will eliminate the need to implement an internal testing framework for years. The product allows you to iterate quickly through your testing lifecycle: from test repository, execution, and reporting. The solution allows teams to collaborate from the use-cases creation to the execution of test cases on a variety of browsers and devices. To execute your test at scale, you can use your own or external robots infrastructure. This allows you to concentrate on your business value. It supports many integrations to speed up implementation, such as Bitbucket and Slack. It is open-source and maintained by many digital and retail players, including La Redoute and Decathlon, Adeo and Norauto.

Tuskr is a powerful and easy-to-use test management tool. You can manage test cases, conduct test runs, and even optimize your testing workload. You can also integrate with your current bug and time tracking software. Tuskr offers a free 30-day trial with sample data during the evaluation. It also offers a generous free plan.

API Tester is a mobile app for IOS and Android for testing and using APIs. It's a completely free API testing tool with a minimalistic interface and, at the same time, rich functionality that allows users to do very complex tasks on a small screen. - Test all types of APIs: REST, GraphQL, WebSocket, SOAP, JSON RPC, XML, HTTP, and HTTPS. - Perform all HTTP request methods: GET, POST, PUT, PATCH, DELETE, HEAD, etc. - Make the API calls with any kind of request data encoding and transfer type like query params, FormData, raw data, etc. Advanced settings allow you to skip TLS, disable redirects, and adjust timeouts. - Import requests or collections by cURL, link, or file from your device: Swagger, OpenAPI, Postman, and YAML collections are supported. - Share requests in a second using a deep link and cURL command. - Powerful GraphQL editor with full-scale experience: body editor with Queries, Mutations, Subscriptions, and syntax support; variables editor, documentation. - WebSocket testing tool is available too: handles connection and message exchange via WS or WSS. So you can easily connect with APIs you are working with from everywhere in the world and leave your laptop at home!

Utilize Telerik Fiddler HTTP(S) proxy to capture all internet traffic between your computer and external sites, allowing you to analyze that traffic, set breakpoints, and manipulate both requests and responses. Fiddler Everywhere serves as a versatile web debugging proxy compatible with macOS, Windows, and Linux platforms. You can capture, inspect, and monitor all HTTP(S) communication, facilitating the mocking of requests and troubleshooting of network problems. This tool is applicable to any browser or application, enabling you to debug traffic across macOS, Windows, Linux, and mobile devices running iOS or Android. It guarantees that the necessary cookies, headers, and cache settings are properly exchanged between client and server. Supporting diverse frameworks such as .NET, Java, and Ruby, Fiddler Everywhere empowers you to mock or alter requests and responses on any website efficiently. This straightforward approach allows for testing website functionality without the need for code alterations. By employing Fiddler Everywhere, you can effectively log and analyze all HTTP/S traffic between your system and the wider internet, streamlining your debugging process.

Tyk is an Open Source API Gateway and Management Platform that is leading in Open Source API Gateways and Management. It features an API gateway, analytics portal, dashboard, and a developer portal. Supporting REST, GraphQL, TCP and gRPC protocols We facilitate billions of transactions for thousands of innovative organisations. Tyk can be installed on-premises (Self-managed), Hybrid or fully SaaS.

ZAPTEST is a leading Free and Enterprise software test automation and RPA tool. Computer Vision technology allows cross-platform digital interface automation for UI and API. This combined with our 1SCRIPT methodology, seamless automation, parallel execution, and unlimited licenses, will result in a testing suite that generates up to 10X ROI. ZAPTEST will automate any procedure you can do via any digital interface (live app or mockup). Discover the unparalleled advantages of partnering with ZAPTEST Our partners are essential in providing businesses with innovative, industry-leading automation solutions that transform software testing and RPA processes. ZAPTEST empowers organizations with a unified automation platform that streamlines both software testing and business operations. Our unlimited licensing model ensures you can scale effortlessly, transforming your business into an agile, efficient powerhouse.

Xano offers a fully-managed, scaleable infrastructure that powers your backend. You can also quickly create the business logic that powers your backend with Xano without writing a single line or use one our pre-made templates to launch quickly and without compromising security or scale. You can quickly create custom API endpoints with just one line of code. Our out-of-the box CRUD operations, Marketplace extensions and templates will accelerate your time to market. Your API is "ready-to use" so you can connect to any frontend immediately and concentrate on your business logic. Swagger automatically documents everything so that you can connect to any frontend easily. Xano uses PostgreSQL, which offers the flexibility of a relational and the Big data needs that a NoSQL solution. You can add features to your backend with just a few clicks. Or, you can use pre-made templates and extensions to jumpstart the project.

Ambassador Edge Stack, a Kubernetes-native API Gateway, provides simplicity, security, and scalability for some of the largest Kubernetes infrastructures in the world. Ambassador Edge Stack makes it easy to secure microservices with a complete set of security functionality including automatic TLS, authentication and rate limiting. WAF integration is also available. Fine-grained access control is also possible. The API Gateway is a Kubernetes-based ingress controller that supports a wide range of protocols, including gRPC, gRPC Web, TLS termination, and traffic management controls to ensure resource availability.

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. Through the GUI, our solution allows you to collaborate, execute and fix your tests and communicate at all levels to ensure test plans and test results are provided with the right level of details. Alithya GoTest is platform-agnostic and will allow you to seamlessly test desktop, web and mobile applications. You will not have to spend months building, maintaining and integrating your test platform into your development workflow, which allows your development team to focus on delivering value and quality. Compared to more traditional solutions, Alithya GoTest is the only tool on the market that allows you to completely test your software from end-to-end using continuous testing in a DevOps process. Contact our top-notch bilingual support team or use our consulting, coaching or online training resources to get up to speed in no time. Benefit from our growing list of pre-made test suites for professional ERP platforms like Oracle Fusion Cloud to ensure updates are not breaking your software solution.

Apidog offers a comprehensive suite of tools designed to streamline the entire API lifecycle, enabling research and development teams to adopt optimal practices for API development focused on design. With a robust visual editor, users can both design and debug their APIs effectively. The platform enhances usability with JSON Schema support, simplifying the process of describing and debugging. Apidog also automates various aspects of the API lifecycle, including test generation based on API specifications, visual assertions, built-in response validation, and integration with continuous integration/continuous deployment (CI/CD) pipelines. Additionally, it facilitates the creation of visually engaging API documentation that can be published to a custom domain or shared securely among collaborative teams. Its local and cloud mock engine produces realistic mock data that aligns with field names and specifications, eliminating the need for script writing. High-quality tools empower your entire team to work cohesively while minimizing redundant tasks. Seamlessly describe your API during testing, and with just a click, generate JSON or XML schemas. You can also easily create test cases from APIs, visually add assertions, and develop intricate test scenarios that incorporate branches and iterations. By leveraging Apidog, teams can not only enhance their efficiency but also foster better collaboration throughout the development process.

HttpMaster is a HTTP debugging and testing tool specialized in testing web API applications and REST web services. Core features: - HttpMaster project to store complete definition of request items. - Broad set of HTTP properties (HTTP headers, URL encoding, etc.). - Dynamic parameters to simulate variations of input data or create global API values. - Response data validation with logical expressions. - Request chaining to use data from previous request with the next request. - Extensive data upload support, including 'multipart/form-data'. - Request data builder for creating request body with an optional parameters. - Request item execution with detailed progress monitoring. - Execution groups to create batches of requests. - Comprehensive execution data review and management. - Basic request tool for ad-hoc execution. - Command line interface. - Support for PDF reports. - Support for cURL commands.

SyncTree strives to be a "Super Connecting Platform" that can easily connect any services you want. With SyncTree, which consists of SyncTree STUDIO, a solution for building backend business logic with block coding, and Block Store, a platform for buying and selling pre-made backend function blocks like App Store, you can organically utilize data and connect services to achieve unlimited service expansion.

You can use your favorite debugging software to locally troubleshoot your Kubernetes services. Telepresence, an open-source tool, allows you to run one service locally and connect it to a remote Kubernetes cluster. Telepresence was initially developed by Ambassador Labs, which creates open-source development tools for Kubernetes such as Ambassador and Forge. We welcome all contributions from the community. You can help us by submitting an issue, pull request or reporting a bug. Join our active Slack group to ask questions or inquire about paid support plans. Telepresence is currently under active development. Register to receive updates and announcements. You can quickly debug locally without waiting for a container to be built/push/deployed. Ability to use their favorite local tools such as debugger, IDE, etc. Ability to run large-scale programs that aren't possible locally.

Introducing Treblle: An agile Software Development Kit (SDK) crafted explicitly for expediting REST-based API development. This cutting-edge toolkit offers unparalleled insights into the intricate metadata of every API request, complemented by real-time monitoring of API traffic. Harness the potency of robust analytics and embrace comprehensive API governance functionalities. Unveil the realm of automated API documentation, empowering your venture with unparalleled efficiency. Treblle transcends the ordinary, introducing automated API security audits for every individual request. The art of streamlining workflows is now within your grasp, while bolstering your defenses through 18+ languages and frameworks, ensuring seamless integration for your enterprise. Elevate your teams' prowess in constructing, shipping, and upholding APIs, all accomplished with unprecedented swiftness.

Enjoy a unified testing experience across various test types. You can utilize the same test scripts regardless of whether you're assessing a web application on numerous browser, operating system, and device combinations, checking the functionality of your APIs, or conducting extensive load tests. Our enterprise-ready SaaS platform, hosted in the cloud by Testable, enables you to execute tests either in the cloud or on-premises with your preferred open-source tools, while we manage the test execution, real-time reporting, detailed analysis, and secure storage in the cloud. Additionally, you have the option to securely deploy our testing platform on your own infrastructure, safeguarded behind your firewall. With modern, scalable, and flexible packaging options, including a convenient one-click Kubernetes Helm package, you can run functional tests across multiple browsers, OS, and devices in a single test run. Furthermore, you will have access to a real-time report that showcases live interactive sessions, videos for each virtual user, screenshots, assertions, performance metrics, trend analysis, and a wealth of additional insights to enhance your testing process. This comprehensive approach ensures that you have everything you need to optimize your testing efforts effectively.

Testing and monitoring your web services has never been simpler. With Assertible's automated quality assurance tools, you can ensure the reliability of your essential infrastructure by testing and monitoring web services throughout various deployments and environments. Assertible acts as a dependable first line of defense against web service failures, offering straightforward and effective assertions for your APIs and websites. By minimizing false positives in your automated quality assurance tests, you can trust that your APIs remain in good health. While keeping your tests current may seem daunting, Assertible streamlines this process by allowing you to automatically synchronize your API tests with the most recent updates to your specifications. As you modify responses, parameters, headers, and additional elements, updating your Assertible API tests becomes a hassle-free task that requires just a simple click to sync. Furthermore, Assertible seamlessly integrates with your existing tools, enabling functionalities like executing your web application tests upon code pushes to GitHub or sending alerts to Slack in case of any failures, thus facilitating a smoother workflow. By leveraging these features, teams can enhance their development efficiency while maintaining high-quality standards.

Craft, troubleshoot, and evaluate APIs with a human touch rather than a mechanical approach. At last, a workflow that you'll genuinely appreciate. Introducing the Collaborative API Design Tool, which provides a platform for creating, validating, and overseeing OpenAPI specifications. This Desktop API client facilitates interactions with both REST and GraphQL. You can make requests and analyze responses seamlessly. Effortlessly create and organize your requests, set up environment variables, manage authentication, produce code snippets, and much more. Dive deep into response details—explore the entire request timeline, including status codes, body, headers, cookies, and additional information. Organize your project with workspaces, folders, and environments, utilizing a drag-and-drop interface for requests, along with straightforward data import and export options. Within a single collaborative API design editor, you can create, modify, lint, troubleshoot, preview, and manage your OpenAPI specifications. Additionally, generate configurations for popular API gateways such as the Kong API Gateway and Kong for Kubernetes. Synchronize your API designs with version control systems like GitHub or GitLab, and deploy directly to API gateways such as Kong with just a click, streamlining your development process significantly. This tool not only enhances productivity but also fosters collaboration among teams in designing robust APIs.

Evaluating and verifying REST services in Java can be more challenging compared to using dynamic languages like Ruby and Groovy. However, REST Assured introduces a level of ease and accessibility akin to those languages within the Java ecosystem, making the process more straightforward for developers. By leveraging REST Assured, Java programmers can streamline their testing efforts and enhance productivity significantly.

Loader.io offers a complimentary load testing service designed to evaluate the performance of your web applications and APIs by simulating thousands of simultaneous connections. You can easily register your application for testing through either the web interface or API. During the testing period, we will generate connections to your application, allowing you to observe the process in real-time. After the test is complete, you can conveniently share the results with your team for further analysis and discussion. This tool is invaluable for ensuring your application can handle high traffic effectively.

RapidAPI Testing offers a comprehensive solution for functional API testing and monitoring, featuring a user-friendly interface and compatibility with all types of APIs, as well as seamless integration with the RapidAPI Marketplace and Enterprise Hub. This tool empowers users and organizations to ensure the reliability of their APIs through sophisticated functional tests designed for thorough validation. It also allows for centralized monitoring of API tests across diverse geographical locations, enhancing overall efficiency by integrating with CI/CD pipelines and fostering collaboration among teams. Furthermore, RapidAPI Testing supports users in crafting tailored functional test flows that ensure robust validation of REST, SOAP, and GraphQL APIs. With an accessible interface, it presents three distinct options for test creation, making it easy for both developers and non-developers to generate visual, automated, or code-based tests that meet their specific needs. Overall, RapidAPI Testing streamlines the API testing process, ensuring that all users can efficiently verify the functionality of their APIs.

Test Mace is a robust and contemporary cross-platform solution designed for API interaction and the creation of automated API tests. It allows users to formulate requests and scenarios while utilizing features such as variables, authentication, an autocomplete function, and syntax highlighting. The tool provides a user-friendly interface that simplifies the development of intricate scenarios. With a single click, users can execute comprehensive regression tests. Additionally, results from requests can be stored in variables for access from various nodes. Users can also retain authorization tokens, response headers, or specific segments of response bodies, enhancing their testing capabilities. Scenarios can be executed across different environmental contexts, which aids in the management of development, staging, and production environments. The built-in authentication methods cater to the most widely-used authentication types, streamlining the process for users. Furthermore, the quick share feature enables effortless sharing of requests with team members; users simply need to click a button to copy the URL of a specific node, allowing them to easily distribute it to their colleagues. This seamless collaboration is essential for effective teamwork and enhances productivity during API testing.