6 Reasons to Choose Postman for API Testing

When I started writing automated API tests in Postman almost 4 years ago, it was a very simple tool for sending API requests. Postman's editor (I write Editor on purpose, because I dare to say it couldn't even be called a development environment, let alone an IDE) didn't know how to autocomplete yet, so writing tests in it was about as comfortable as in Notepad. It didn't have the possibility of global search, let alone code text replacement, so we solved search&replace via notepad++, the generated html reports were black and white, and you could read practically nothing from them. Instead of data-driven tests, which Postman couldn't handle back then, we just copied and copied requests until we ended up with 300 requests in one collection, which differed only in a few parameters, and when trying to run such a test, the whole editor froze for several minutes—terrible times! 

However, as time went by and new and better features came with the next versions of Postman that solved the above-mentioned problems, the popularity of this tool grew rapidly not only among developers but also testers, and I dare say that nowadays it is one of the most dynamically developing tools for API development and testing.

In this article, I would like to present you some reasons why you should choose Postman for API testing. I will discuss these advantages of Postman one by one:

It's free

In the current economic climate, many companies are reluctant to invest in testing tools, so the purchase price may be a deciding factor. Postman is open source, and therefore, free. It also provides a paid version for teams, companies, or entire corporations, but the free version is fully usable for a variety of projects. The limitations of the free version can be found in the sharing of requests, the number of API monitors, or queries to the Mock server, which can be bypassed. In addition, Postman does not limit the free version to private use, so it can be easily deployed on larger commercial projects.

It is simple

Getting started writing tests in Postman is relatively easy. With a basic knowledge of any scripting or programming language, creating your first test is a matter of minutes. A number of free tutorials and tutorials can be found on the internet, both on the official Postman website, as well as on YouTube, StackOverflow, or elsewhere. Postman's knowledge base is really broad, and you can find several solutions to every problem. However, if you want to learn Postman really quickly and efficiently, there's nothing easier than signing up for our online course, which we'll soon be launching in an improved form.

REST, SOAP, and GraphQL

A lot of people know Postman as a tool for testing REST APIs, but nowadays, it can work just as well with SOAP APIs or GraphQL APIs. For the latter, Postman even allows you to import a GraphQL schema and then autocomplete based on it when writing API requests, making your job significantly easier.

Integration with CI/CD and other tools

Tests written in Postman can be run within virtually any Continuous Integration Pipeline using a simple commandline tool called Newman. It allows you to run tests with different parameters in the same way as they are run in Postman. It can then generate reports in a variety of formats, including the ability to create custom report templates. We found htmlextra newman reporter the most useful, which generates dynamic drop-down reports including API request and response information, including header and body. So you will get complete information about the potential problem.

In addition to the standard CI/CD integration, a number of other tools have emerged in the last couple of years that Postman can be interfaced with. Some of the best-known ones include BitBucket, GitHub, GitLab, Dropbox, Slack, Microsoft Teams, and APIMatic. It's possible to collaborate with colleagues on tests or, for example, have Postman send notifications about other team members' activity to your Slack. It should be noted, however, that the integration with code repositories is relatively new, and you won't yet find the usual Git commands you're used to from other tools. However, we can expect that such features will come in a future release.

Speed of tool development

As mentioned above, Postman is developing very dynamically, and with each release comes not only a number of bug fixes but also new features. Few other tools can respond so quickly to the demands of their users. I believe that it will soon surpass other tools on the market with its capabilities and become an industry standard. So it is high time to get acquainted with Postman and get it on your side.

API Mocking

API mocking is one of the interesting features that you can try out in the free version of Postman (although you have to pay for its wider use). By mocking API responses, you can start writing tests even before the developers finish their work. You can even create your tests and provide them to developers before they start developing, which is a great application of the test-driven approach in practice. This approach not only speeds up development but also promotes a mutual understanding of the expected behavior of the application. It doesn't happen that the developer interprets the requirements differently than the tester, or, thanks to automated tests, this split is discovered during the development process and not two hours before the end of the sprint.

Conclusion

Postman is undoubtedly an interesting tool for API development and testing, and it is becoming increasingly popular among developers and testers. Although it is far from perfect, its strength lies in the fact that it helps bridge the gap between the world of programmers and testers. Having both using the same tool makes it easier for them to share tests and achieve better collaboration. This ability is crucial in the world of agile application development.

Autor: Lucie Lavičková

Lucie Lavičková has been working in testing for over 8 years and has gained experience working on projects in the Czech Republic and Germany for international companies such as IBM, Commerzbank, Datev, and NEORIS/CEMEX. Currently, she works at Tesena as a Senior Test Engineer, specializing in test automation in agile projects.