In 2025, APIs are more than just a backend tool—they are the foundation of modern applications. From mobile apps to cloud platforms, APIs power the connections that make services interactive and scalable. However, these APIs need rigorous testing to ensure functionality, security, and performance. That’s where choosing the right software for API testing becomes essential. It helps detect bugs early, validate responses, simulate real-world usage, and maintain application reliability across updates.
If you’re building, managing, or deploying APIs, this list of the top API testing software in 2025 will help you find a tool that fits your workflow and project scale.
What is API Testing?
API testing is a type of software testing that focuses on verifying that Application Programming Interfaces (APIs) function correctly, securely, and reliably. Application Programming Interfaces (APIs) are rules that let different software systems communicate. They act as messengers, sending and receiving data between apps and servers, enabling smooth and secure interactions.
Instead of testing the user interface, API testing examines the logic layer of the application to ensure that data is processed and transferred accurately between systems. It involves sending requests to API endpoints and validating the response data, status codes, performance, and error handling. This form of testing is essential for identifying issues early in the development cycle and ensuring that integrations between applications work as intended.
Also Reads : WordPress Plugins for Product Filtering
List of Software for API Testing
1. Postman
Postman remains a leading choice for API testing due to its balance of usability and power. With support for REST, SOAP, and GraphQL, it allows developers to build and run requests, validate responses, and automate test cases. Postman’s built-in scripting features, mock server capabilities, and team collaboration tools make it ideal for agile teams. Whether you’re running exploratory tests or full-scale CI/CD integrations, Postman is a reliable all-rounder in the world of software for API testing.
2. SoapUI
SoapUI, developed by SmartBear, is a veteran tool that remains relevant in 2025. It’s perfect for teams needing in-depth functional and security testing, especially for SOAP-based services. The open-source version provides plenty of features, while the Pro version adds advanced data-driven testing and reporting. Its flexibility, scripting support, and integration options make SoapUI a solid enterprise choice for software for API testing.
3. Katalon Studio
Katalon Studio offers a complete test automation platform that handles API, web, desktop, and mobile testing. Its intuitive interface allows testers to create powerful API tests without needing to code, while advanced users can take full control with Groovy scripting. Katalon supports REST, SOAP, and GraphQL, making it suitable for diverse testing environments. As an all-in-one solution, it’s especially valuable for QA teams looking to unify their testing approach with modern software for API testing.
4. Swagger (OpenAPI Tools)
Swagger, best known for API documentation, also delivers powerful testing functionality. With Swagger Inspector and SwaggerHub, teams can test API endpoints, validate schemas, and collaborate in real time. Swagger’s OpenAPI specification helps standardize how APIs are defined and tested, making it easy to create mock servers and automate tests. If you’re following an API-first development strategy, Swagger offers a seamless ecosystem for design, documentation, and software for API testing.
5. Rest Assured
Rest Assured is a Java-based framework that gives developers total control over API testing through code. It integrates effortlessly with JUnit and TestNG and is best suited for RESTful services. With concise syntax and reusable scripts, Rest Assured is powerful, especially in continuous integration setups. For teams working in Java environments, it’s one of the most effective pieces of software for API testing that offers detailed and flexible control over testing logic.
6. JMeter
Apache JMeter has long been favored for performance testing, but it also shines in API functional testing. Supporting REST and SOAP services, JMeter allows testers to simulate high traffic loads and measure API performance under stress. Its rich visualization tools, scripting support, and ability to handle complex test scenarios make it a great option when you need to combine performance and functionality in one software for API testing tool.
7. Paw (macOS Only)
For macOS users, Paw offers a polished and feature-rich experience. It’s designed specifically for API development and testing, with native support for REST, GraphQL, and SOAP. Paw includes features like advanced request editors, code generation, and dynamic values, making it a favorite among iOS and macOS developers. Its intuitive interface and powerful backend earn it a strong position among modern software for API testing solutions.
8. Insomnia
Insomnia has quickly become a favorite among developers who want simplicity with power. This open-source platform supports REST, GraphQL, and WebSocket testing with a clean, distraction-free UI. Features like environment variable management, request chaining, and real-time previews make it highly effective. Whether you’re an individual developer or part of a collaborative team, Insomnia is a versatile and lightweight software for API testing solution.
9. Hoppscotch
Hoppscotch, formerly known as Postwoman, is a web-based, open-source API testing tool that’s lightweight yet powerful. It offers instant feedback, real-time WebSocket testing, and support for REST, GraphQL, and more—all within the browser. Its fast performance and collaborative interface make it ideal for developers looking for a browser-first software for API testing experience that doesn’t require heavy installations or configurations.
10. Tricentis Tosca
Tricentis Tosca brings enterprise-grade capabilities to the table with its model-based testing approach. It allows testers to design robust, automated API test cases without writing any code. Supporting a wide range of protocols, including REST, SOAP, JMS, and more, Tosca integrates with enterprise CI/CD pipelines and compliance frameworks. It’s best suited for organizations with complex systems that require scalable and auditable software for API testing.
Find the Right API Testing Tool for your Needs
The API landscape continues to expand, and so does the need for accurate, scalable, and efficient testing. Choosing the right software for API testing depends on your team’s skill set, project complexity, and development environment. Tools like Postman and Insomnia offer user-friendly interfaces for quick testing, while options like Rest Assured and JMeter provide more control and scalability for advanced users. If your goal is enterprise automation and compliance, platforms like Tosca or SoapUI Pro will deliver the depth you need.
As you head into 2025, investing in capable API testing tools will help your applications stay fast, secure, and reliable—no matter how complex your infrastructure becomes.
Interesting Reads
Best Software for Parental Control
