Best Free API Testing Tools of 2025

Our robust API solution will elevate your development process and ensure performance, stability, and reliability with every release. Seamless integration with CI/CD to create a cohesive development pipeline. API Swan was created with the mission of creating a software testing tool that is affordable and reliable, specifically designed for early-stage startup engineering teams. Ship products 10X faster and catch more bugs. Monitoring of applications 24x7 for uninterrupted performance. Automatically generates regression tests based on network traffic. Automated test case design that is seamlessly integrated into your workflow. Automatic documentation of APIs and Schemas, saving time.

Pynt, an innovative API Security Testing Platform, exposes verified API threats by simulating attacks. We help hundreds companies, including Telefonica, Sage and Halodoc to continuously monitor, categorize and attack poorly secured APIs before hackers do. Pynt’s uses a unique hacking technology and an integrated shift-left strategy, using home-grown attack scenario, to detect real threats. It also helps to discover APIs and suggest fixes for verified vulnerabilities. Pynt is trusted by thousands of companies to protect the No. As part of their AppSec strategies, a number of companies rely on Pynt to secure the no.

All-in-one solution for test automation You can get started quickly and scale up to any level for any team. Katalon Studio Robust testing on all platforms Productive IDE allows you to easily create automated tests for all platforms and OSs, regardless how complex your application is. A powerful recording utility that stores all UI elements in a single place to maximize reusability. For beginners, codeless experience Experts can extend their testing capabilities. Set up projects Templates for projects with built-in features Start immediately with pre-made templates, test cases libraries, keywords, object repositories, and other useful tools. All types of end-to-end testing at one place Uniquely perform web and mobile testing - all within a single project

BlazeMeter's enterprise-ready platform is open-source and enterprise-ready. It combines all the functionality you need for testing to move left and right. You can create new tests, reuse existing scripts, and then run them at scale as part your continuous testing strategy. You can test and generate detailed reports and see historical trends. Spend more time innovating and less time maintaining your toolchain. Continuous testing is crucial to delivering quality, volume, speed, and reliability. However, integrating, maintaining and learning multiple tools is a waste of time and resources. BlazeMeter is an intuitive platform that does everything. BlazeMeter provides complete shift left testing so that you can innovate and impress the market. BlazeMeter has all the components needed for continuous shift left testing. You can use CLIs, APIs and UIs. You can save a lot of time with setup, maintenance and learning.

Eggplant empowers organizations to create incredible digital experiences. We help businesses monitor, analyze and improve their customer experience. Eggplant is used by companies around the world to outperform their competitors, increase productivity, and delight customers. How does Eggplant work? How? By dramatically improving the quality, responsiveness and performance of their software apps across different interfaces and platforms, browsers and devices -- including mobile, IoT and desktop -- in agile, DevOps and innovative application and data environments.

You can design, debug, test, and maintain APIs like a human. Not a robot. Finally, a workflow that you will love. The Collaborative API Design tool for designing, testing, and managing OpenAPI specifications. The Desktop API client for REST or GraphQL. You can inspect the responses and make requests. Create and group requests quickly, specify environment variables, authentication, and generate code snippets. All details about the responses are available. View the entire request timeline, status codes and body. You can also view headers, cookies, headers, and more. You can easily import and export data by creating workspaces, folders and environments. All of your OpenAPI specifications can be edited, lint-ed, debugged, viewed, and managed in one collaborative API design editor. Generate configuration for common API gateways like the Kong API Gateway and Kong for Kubernetes. You can sync your API designs with source control like Github / Gitlab and deploy directly to API Gateways like Kong with just one click.

Validating REST services in Java can be more difficult than in dynamic languages like Ruby and Groovy. REST Assured brings the simplicity and ease of these languages to the Java domain.

Loader.io offers a free load testing service that allows users to stress-test their web-apps and apis with thousands concurrent connections. Register your app using the API or web-interface to test it. For the duration, we'll simulate connections to you application. You can monitor the test in real time and share the results with your colleagues.

RapidAPI Testing provides functional API testing and monitoring solutions. It offers an intuitive UX, supports any API type and integrates with RapidAPI Marketplace or Enterprise Hub. RapidAPI Testing allows users and enterprises to: Ensure API Functionality - Create complex functional tests for deep validation APIs. Centralize Monitoring – Monitor and manage API tests across multiple geopolitical boundaries. Increase efficiency - Connect to the CI/CD pipeline and collaborate across teams. Natively integrate with RapidAPI Marketplace or Enterprise Hub. RapidAPI Testing allows you to create functional test flows that can be customized and validate REST, SOAP, or GraphQL APIs. A simple interface allows users to choose from three test generation options, allowing both developers and non-developers the ability to create code-based, visual, or automated test generation.

Test Mace is a powerful cross-platform tool that allows you to work with an API and create automated API tests. You can create scenarios and requests using variables, authentication and syntax highlighting. Our simple UI interface makes it easy to create complex scenarios. You can perform complete regression testing in just one click. You can assign a request result to an variable and gain access from other nodes. You can save authorization tokens, response headers, and parts of a response. Run your scenarios in different environment contexts. This can be used to organize stage, development, and production environments. If you are using one of the most common types, embedded authentication methods will allow you to perform authentication. To share your request with colleagues, you can use the quick share feature. To copy a specific node's URL, press a button. You can now send the url to your teammate.

Our generator allows you to create JavaScript or CoffeeScript test scripts. Write a script to set the request parameters, and then validate the response. Ping-API will run the test script on global servers in U.S.A, Japan, Germany, Singapore. Schedule testing to inspect your APIs. We will send you the failure information via email, Slack, and HipChat. Ping-API allows users to create JavaScript and CoffeeScript test scripts to test their APIs. Write script to set request URL parameters, headers, and body. Write script to validate headers and body. Script generator. Programming is not a problem. The generator will generate a test script if you just set the parameter for your API. It's easy! This is the use case for web developers. If my web goes down or the response is not expected, please notify me. Ping-API schedules your tests every minute or hour. We will notify you if the test fails.

Bright Security is a developer-centric Dynamic Application Security Testing solution (DAST). This allows organizations to ship secure APIs and applications quickly and economically. Its method allows for quick and iterative scanning to identify critical security flaws early in the SDLC, without compromising quality or delivery speed. Bright empowers AppSec teams with governance to secure APIs and web applications while allowing developers to take control of security testing and remediation. Bright's DAST solution, unlike legacy DAST solutions that were designed for AppSec professionals, is easy to deploy and finds vulnerabilities late in the development process. It can be deployed in the Unit Testing phase, and run through the entire SDLC, learning from each scan and optimizing. Bright helps organizations detect and fix vulnerabilities early in the SDLC. This reduces risk and costs.

Hackers are looking for loopholes in API logic. Learn how to protect APIs and prevent data leaks and breaches. APIsec identifies critical flaws within API logic that can be exploited by attackers to gain access to sensitive information. APIsec pressure-tests every API to make sure no vulnerabilities can be exploited. This is in contrast to traditional security solutions which look for common security problems such as cross-site scripting and injection attacks. APIsec will reveal vulnerabilities in your APIs before they are released to the public. This allows you to identify potential exploitable endpoints and prevent hackers from exploiting them. To identify potential vulnerabilities in your APIs, run APIsec tests at every stage of the development process. This will help you to find them before they go into production. Development doesn't need to slow down for security. APIsec runs at the speed DevOps and gives you continuous visibility into your API security. APIsec tests can be completed in minutes, so there's no need to wait for the next scheduled Pen-test.

TeejLab is a leader in applying machine learning and data science to assist organizations with the evolving challenges of API economy. The only industry solution for API governance at global enterprises. How secure and compliant are you with legacy apps and mainframes communicating via APIs with internal and external information systems? The world's first software composition analysis tool for discovering hidden, private or public APIs through a curated knowledge database. TeejLab is doing Web APIs what Google did for websites. TeejLab's modular product portfolio is designed to address the diverse API Governance needs of communities and enterprises, while also allowing for flexibility to add new capabilities as they evolve. We have the right product for you, whether you are an engineer looking to benchmark APIs, or a producer or consumer of APIs who is ready to expand your product range.

You can submit API test requests via UI form. Or invoke EthicalCheck API by using cURL/Postman. Request input requires a public-facing OpenAPI URL, an API authentication token valid at least 10 minutes, an active license key and an email. EthicalCheck engine automatically creates custom security tests for APIs. It covers OWASP API Top 10 List. Automatically removes false negatives from the results. Creates a developer-friendly report and emails it to. According to Gartner APIs are the most common attack vector. API vulnerabilities have been exploited by hackers/bots, resulting in major security breaches across thousands of organizations. False positives are automatically separated from real vulnerabilities. Generate enterprise-grade penetration test reports. It can be shared with customers, partners, developers, and compliance teams. EthicalCheck works in the same way as a private bug bounty program.

Describe examples of API requests and responses. Define API logic in natural language. Test your API endpoints, and fine-tune prompt, response structure, or request structure. Integrate API endpoints into your applications with just a click. In less than one minute, you can build and deploy sophisticated application logic with no code. No need for individual LLM accounts. Sign up for Backengine and get started building. Our super-fast backend architecture is available immediately. All endpoints have been secured and protected, so that only you and your application can use them. Manage your team members easily so that everyone can work on Backengine endpoints. Add persistent data to your Backengine endpoints. A complete replacement for the backend. Use external APIs to integrate your endpoints.

Navigate easily through a clutter-free interface that allows you to focus on the important things: efficiently testing and collaborating APIs. Firecamp's user-friendly interface, along with a variety of powerful features streamlines API development workflows and improves collaboration between team members. Set values to variables that can be reused across the entire platform. Publish beautiful API documentation to your team and community. Run API Collection tests in the terminal, or in CI/CD pipeline. Test and debug auth endpoints using a variety of supported auths.

One APIMarketplace is a platform-independent enterprise-grade API marketplace that allows you to publish, consume, and collaborate. It will accelerate your API journey and enhance the developer experience. Reduces API complexity and sprawl by operationalizing APIs. This includes making them discoverable and consumable. It also makes them easy to access and collaborate. One APIMarketplace reduces the time to market through the effective adoption of APIs, API usage and performance insights. Empower developers to adopt APIs faster with intuitive documentation, community engagement and resources. One APIMarketplace simplifies the discovery and use of your APIs. This ensures a hassle-free and smooth experience for both developers and businesses. Access detailed documentation and test APIs before integration. Our analytics dashboard provides insights into API usage and performance as well as user behavior.

Testfully has it all, from powerful API client features to advanced monitoring and testing. Enjoy the flexibility of cloud-based and offline-only storage. The seamless team collaboration and easy migration are all available in one multiplatform tool. Transfer your data directly from Postman or Insomnia into Testfully. Set global, folder, and environment variables that are scoped by workspace or user. Create any HTTP request by customizing auth, parameters and headers. Add teams, assign roles and control folder access. Supports major schemes such as OAuth2 to streamline and secure authorization. Testfully allows for quick and effective testing, without the need to code. Advanced API testing is now accessible and hassle-free. With just one click, execute all requests in a directory simultaneously, sequentially or randomly. Validate responses and conduct contract testing using a declarative form. No coding is required.

Hoverfly Cloud, a SaaS API Simulation solution owned by iOCO allows you to speed delivery, reduce costs and get resilient software on the market faster. Hoverfly Cloud, designed from the ground-up for integration, automation and performance, allows developers and testers to replace APIs that their applications rely on with flexible lightweight simulators. This allows developers and test engineers to decouple the development and testing processes from unreliable and expensive test systems, and restrictive API sandboxes. API simulations can be configured in a way that they reproduce unexpected API behaviors, such as high latency and random failures. This allows applications to respond gracefully to API misbehaviors. Hoverfly Cloud has extremely low running costs, even when performing complex and extreme testing. Create API simulations and mocks in just minutes, without the need for expensive, complex features.

Create endpoints quickly, generate custom data and perform operations using a RESTful Interface. Define the resource schema, and data generators per field. Set up relationships between resources and generate endpoints automatically. MockAPI allows you to easily mock up APIs. It is meant to be used as a prototyping/testing/learning tool.

Sparrow is a complete tool set that helps R&D teams achieve excellence in API development by focusing on design first. Use cURL for API requests and support methods such as GET and POST. It simplifies API interaction, handling headers and data easily. A collaborative open-source solution for API creation, allowing the creation of exceptional APIs to be streamlined. Collaborations allow developers to shift their development practices early in the process. This leads to faster development and higher-quality APIs. Parallel testing is easy across multiple environments, so you can get insights on the move. Sparrow provides powerful tools to secure and manage your API data, along with self hosting capabilities. Users have complete control over their test environment. Sparrow's latest insights, developments, and resources will keep you up to date.

Hoppscotch helps you create and test APIs quickly, allowing you to ship your products faster. Create APIs faster, document them and share them automatically. Develop without switching tabs from prototyping to production. Hoppscotch has everything you need to develop APIs easily. Create workspaces for teams. Control access to workspaces. Work with your team in real time. Deploy Hoppscotch to your own servers. Organize requests into collections or folders, and share them within your team. Manage your environment variables, and use them anywhere. View and manage the history of your requests. Modify headers and authenticate requests. Generate random data. Test your APIs, and write assertions to be used in the response. Use Hoppscotch with your native language. We support over 30 languages. Track all activities in your workspace. Who did what when? Login to Hoppscotch using your existing SSO provider. Manage your users, workspaces and more.

An API Monitoring (Runscope API test) is a series of HTTP requests executed in a sequential order to evaluate the correctness, uptime, and performance of an API. You can define Assertions for each step of the test to validate response data, and Variables that will extract data for subsequent requests. If all assertions pass, the test is considered passed. If any assertion fails or another error occurs, the test is deemed to be failing. Customers shouldn't be telling you about downtime or breakages. Runscope supports all the notification tools you use, including PagerDuty and HipChat, Slack, HipChat email, webhooks, and more. Monitor service performance to quickly detect and fix API problems. With the API Dashboard, you can stay ahead of intermittent failures so they don't become major problems. Verify that your API calls are structured and contain the information you expect. Flexible assertions that are powerful and easy to use give you complete control.

In 30 minutes, you can create an API. It can be shared with your customers or colleagues. You can let them use the API mock to give your API a spin without writing any code. You can iterate, rinse and repeat. Coding can wait until your developers know what they really need.