Today, the tolerance of errors in software applications is quite low. When most of the users encounter an error while using an application, the rate of reusing that application gradually decreases. Errors undermine users’ trust in applications. For this reason, APIs developed in many software applications are regularly tested. API testing tools are useful tools for both paid and free public APIs to be tested recently.
Both paid, and free public APIs can be easily tested, and testing tools help developers and businesses to notice errors that may occur in the live environment. API testing is therefore considered one of the most important steps in software development. In this article, we’ll explain why API testing is important. Then we will discuss Postman, the most popular API testing tool today. Finally, we will explain how to test an API with Postman.
Table of Contents
Why is API Testing Important?
Testing an API is the testing process of testing a component of a software or service called the Application Programming Interface (API). APIs are services that enable software to exchange data between different components. API testing is very important for several important reasons:
- Functionality Check: API tests help verify that an API works correctly and is functional as expected. It is important for the developed application’s continuity to ensure that the API performs all the functions it needs to perform correctly and to check that the interaction with the other components of the system is compatible.
- Data Integrity: Data accuracy is critical as APIs enable data exchange between applications. API tests help verify that the API outputs the correct data with the correct data input. Thus, developers can easily make sure that the data converted or processed by the API is correct.
- Performance and Load Testing: APIs are often heavily used by multiple users or applications. Developers can run API tests to evaluate the performance of the API and how it performs under heavy load. Performance metrics such as API speed, response time, and how it scales under load are quickly determined by testing.
Explore in-depth information on API testing and approaches!
Why is Postman the Most Popular API Testing Tool?
Postman is the most popular testing tool today, the choice of developers for testing APIs in software applications. Here are some reasons why Postman is the most popular testing tool today:
- Ease of Use: Postman has a user-friendly interface. So, it makes it easy to create, submit, debug, and manage API tests. It allows developers to quickly create API tests with user-supportive features such as drag-and-drop operations, auto-complete features, and ready-made templates.
- Multi-Platform Support: The Postman testing tool can be used on different operating systems, such as Windows, macOS, and Linux. It also has a browser version available. This gives developers a consistent experience across different platforms.
- Easy Sharing and Collaboration: Postman makes it easy for developers to share API test collections and documentation. Developers can easily share test cases with other developers, collaborate and get feedback. Collaborative workspaces make it easy to share and synchronize API tests between teams.
How to Test APIs with the Postman?
In this section, we will learn how to test an API with Postman easily.
Get a Free API from the APILayer
Before we start API testing, we must have a free API product to test. For this, we will subscribe to an API product from APILayer, which has more than 90 free API products and is today’s most popular API marketplace.
There is a very popular IP geolocation API listed under bestseller on APILayer. Its name is the ipstack API. Let’s sign up for the free subscription plan where the ipstack API offers 100 requests for free and get an API key.
Download the Postman Testing Tool
To use the Postman testing tool, we will download it. For this, let’s download this tool from Postman download page to our computer and install it.
Create a Collection
Let’s start the application after downloading and installing the Postman testing tool. After starting the application, the following screen will welcome us.
Before creating a collection, let’s clarify the concept of collection in Postman. The collection allows us to save multiple requests as a group and share them with others when needed. In this way, it allows us to keep the requests that we already use while working on a project at hand regularly.
Now we can create a collection. For this, let’s follow the ‘New >> Collection’ steps in order and name our collection ‘Geolocation’. The image of the collection we created will look like this.
Create a Request and Send It
Now we will create an API request in the collection we have created. For this, right-click on the ‘Geolocation’ collection and press ‘Add Request.’ Then the ‘New Request’ window below will open.
Let’s click ‘New Request’ to name and update our request with ‘Retrieve Geolocation Information.’ Let’s put the following URL of the ipstack API in the ‘Enter request URL’ field.
Let’s put our API key directly in this URL’s ‘YOUR-ACCESS_KEY’ field. Now we can test our free public API. For this, let’s press the ‘Send’ button.
We get the response after pressing the ‘Send’ button.
Additionally, analyzing our API response is pretty easy with Postman. First of all, when we move our mouse pointer over ‘488 ms’ to analyze the event time, the data we get will be as follows.
Then we can examine ‘1.01 KB’ to analyze the response size.
To sum up, competition in software applications minimizes the error tolerance in these applications. While providing the best experience to users in their applications, businesses strive not to show them any errors. Today, with the API tests performed after the development phase, the error rates of the applications in the production environment are minimized. Popular testing tools like Postman allow developers to easily test their APIs. Thus, they and businesses can increase customer satisfaction and easily get ahead of their competitors.
Q: What is the Postman?
A: The Postman testing tool is a powerful software tool for testing, documenting, automating, and collaborating with APIs. Postman allows you to create, send, debug, and manage API tests through a user-friendly interface. It also provides API documentation, automation, and collaboration features.
Q: How to Test an API?
A: There is more than one way to test an API. Chief among these is using an API testing tool. With the API test tool, developers and testers can quickly test their desired API products with an interface.
Q: What are the Benefits of API Testing?
A: API testing is a very important step for businesses and developers in the software development process and has many benefits:
- Functionality Check
- Data Accuracy
- Performance and Scalability
- Error Checking and Exception Handling
- Security Tests
- Backward Compatibility
Q: What are the Popular API Testing Tools?
A: There are many API testing tools available today. The most popular of these tools are as follows:
Q: Why Should I Choose Postman for API Testing?
A: Here are a few key reasons why you should choose the Postman API testing platform:
- Ease of Use
- Multi-Platform Support
- Comprehensive Features
- Broad Integration Support
- Sharing and Collaboration Ease
- Automation Capabilities
- Great User Community and Resources