I discussed in my last blog post about what makes an effective API testing tool and now I want to spend my next few posts looking at the pros and cons of different API testing tools to help you decide which one is the best for your specific use case.
And I will start off with a tool that is arguably one of the most popular in the API testing space – Postman. Postman is a powerful tool that allows for the simple formation of different API messages easily, integrating with different formats, whether it be REST, SOAP, or any customized format. It’s this simplicity of use that perhaps makes it so popular, though it’s not all about ease of use as it boasts a comprehensive set of features that allows for group sharing, creating parameters and variables to make it easy to change data where needed and some playback features that allow for automation.
Postman primarily functions as a client-side application that users install on their local machines. It is available as a standalone desktop application for Windows, macOS, and Linux, as well as a web version accessible through web browsers. The tool can be used for free, but many of the advanced features do require a license to utilize.
Postman allows users to create API requests using different HTTP methods (GET, POST, PUT, DELETE, etc.), set headers, define request parameters, and specify authentication details that it can then validate in the responses received. The tool allows users to make collections of different related APIs that can be organized hierarchically and include multiple requests along with associated metadata, such as descriptions, examples, and tests. It then allows users to configure Environments where users define variables and configurations specific to different testing environments (e.g., base URLs, API keys) that can be used across multiple requests.
Along with manually hitting API endpoints, Postman also provides a JS-based built-in scripting language that allows users to define assertions and conditions and then verify the correctness of API responses, and validate status codes, response structures, or specific data elements. The tool's automation capabilities are very capable, though its best features are hidden behind its licensing model, meaning that companies that are not willing to pay this are better off utilizing another open-source framework or designing their own to automate their APIs.
Outside of its testing features, Postman also provides its own API, allowing users to programmatically interact with Postman's features and functionalities. The Postman API enables developers to automate tasks, integrate Postman into their workflows, and extend the capabilities of the tool.
Below is a brief history of the development of Postman:
Inception (2012): Postman was initially created by Abhinav Asthana as a side project in 2012 while he was working at Yahoo. He recognized the need for a tool that could simplify API testing and documentation. The first version of Postman, known as "Request Maker," was released as a Chrome extension. It gained popularity quickly among developers for its simplicity and usefulness in testing and debugging APIs.
Founding of Postman Inc. (2014): In 2014, Abhinav Asthana co-founded Postman Inc. with Ankit Sobti and Abhijit Kane to further develop and expand the tool. They rebranded it as "Postman" and started working on new features and enhancements. Alongside the Chrome extension, Postman launched a standalone desktop application compatible with Windows, macOS, and Linux. This expansion broadened its accessibility to a wider range of developers.
Rapid Adoption and Growth (2014-2016): Postman quickly gained traction and popularity among developers worldwide. It became one of the go-to tools for API testing, documentation, and collaboration, driving significant user adoption and growth.
Funding and Series A (2015-2016): In 2015, Postman Inc. secured $2 million in seed funding, followed by a $7 million series A funding round in 2016. These investments enabled the company to expand its team and accelerate the development of new features.
Collaboration and Teamwork Features (2016): Postman introduced collaboration features that allowed teams to work together seamlessly on API development and testing. These features included sharing collections, collaborating on requests, and managing roles and permissions.
Postman Pro and Enterprise (2016): To cater to the needs of larger teams and organizations, Postman introduced paid versions called Postman Pro and Postman Enterprise. These versions offered advanced collaboration features, enhanced security, and additional capabilities.
Introduction of Postman Cloud (2019): Postman launched Postman Cloud, a centralized platform that allowed teams to manage their API development and testing workflows. It offered features like version control, team collaboration, and API documentation.
Public API Network (2020): Postman launched the Public API Network, an open directory where developers could discover, explore, and consume public APIs. It provided a platform for API providers to showcase their APIs and facilitated integration and collaboration among developers.
Continued Innovation and Growth (2020-present): Postman has continued to innovate and release regular updates, introducing new features, enhancements, and improvements to the tool. It actively engages with the developer community, gathers feedback, and incorporates user suggestions into its roadmap.
The pros and cons of Postman
Its history is important, but as the features of the tool have evolved it has become even more difficult to assess all of its pros and cons - so hopeful this below list will help.
Pros:
User-Friendly Interface: Postman provides a clean and intuitive interface, making it easy for developers and testers to understand and navigate the tool.
API Testing and Automation: Postman offers robust testing capabilities, allowing users to create and execute tests for APIs. It supports both manual testing and automated testing workflows.
Request and Response Management: Postman allows users to create and manage API requests and responses effectively. It supports various HTTP methods, headers, parameters, and authentication types.
Collections and Environments: Postman's collection feature allows users to organize and group API requests, making it easier to manage and share them with team members. Environments enable users to define variables and configurations for different testing environments (e.g., development, staging, production).
Collaboration and Teamwork: Postman provides collaboration features that facilitate teamwork and collaboration on API development and testing. It allows team members to share collections, collaborate on requests, and manage roles and permissions.
Automation and Integration: Postman integrates well with other development tools and services, enabling seamless workflow integration. It supports integrations with version control systems, build systems, CI/CD pipelines, and more.
API Documentation: Postman offers features for generating and publishing API documentation. It allows users to add detailed descriptions, examples, and annotations to API endpoints, making it easier for developers to understand and consume APIs.
Mock Servers: Postman's mock server functionality allows developers to simulate API endpoints and responses. This feature is particularly useful for parallel development and testing when the actual backend is not available.
Monitoring and Analytics: Postman provides monitoring and analytics capabilities, allowing users to track API performance, response times, and usage patterns. This data can help identify bottlenecks and optimize API performance.
Vibrant Community and Support: Postman has a large and active community of users and developers. It offers extensive documentation, tutorials, and forums for support, ensuring users have resources to troubleshoot issues and seek guidance.
Cons:
Automation Challenges: While Postman offers an automation capability, most of the critical features require a license and unless you're prepared to lock yourself into using their framework and paying a license fee, it is often best to rather establish your own API testing framework instead.
Limited Browser Support: While Postman started as a Chrome extension, it has expanded to support other operating systems. However, browser compatibility may still be limited, and some features may work differently across different browsers.
Resource Intensive: Postman can be resource-intensive, especially when dealing with large API collections or performing complex test scenarios. It may consume significant memory and processing power, impacting system performance.
More advanced features require licensing: While Postman is perfectly usable as a tool for free, some of the more useful collaboration, mocking, and monitoring features that make it easier for teams to work collaboratively on API testing and automation – do require a license.
Limited Data Management: Postman lacks advanced features for data management and manipulation, which could be essential for certain use cases.
Version Control Challenges: Although Postman integrates with version control systems, managing and resolving conflicts in collaborative environments can be challenging, especially when multiple team members are working on the same collection simultaneously.
Limited Native Support for Non-REST APIs: Postman is primarily designed for RESTful APIs. While it can handle non-REST APIs, its features and capabilities may be more limited in those cases.
Lack of Native Performance Testing: While Postman offers monitoring and analytics features, it does not provide built-in load testing or performance testing capabilities. Users may need to integrate with third-party tools for comprehensive performance testing.
Reasons to Select Postman:
You have a backend architecture and a big focus on API testing and need a tool that allows your team to quickly get APIs tested and automated.
You have a mature test automation framework already in place and so can use Postman to supplement your testing effort or you don’t mind paying for Postman to get many of these features.
Your existing UI automation tool is not meeting your API testing needs.
Postman is often one of the first tools most companies go to for their API testing and for good reason. It offers all the features you would need to adequately test and automate APIs and enables teams to quickly deliver on your API testing needs without needing to learn a new complicated tool or framework.