What is Interface Testing? Definition, Types, Strategy, Tools – Devstringx

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What is Interface Testing? Definition, Types, Strategy, Tools – Devstringx

What Is Interface Testing?

The testing that is done to verify the interface functionality calls Interface testing which defines as a software testing type that verifies whether the communication between two different software systems is done correctly.

Interface testing


Common Components of Interface Testing Include

  • Web server and application server interface.
  • Database server and application server interface.

When and Why Should We Test an Interface?


When and Why Should We Test an Interface


Phases of Interface Testing in an Interface Life-Cycle

There are 03 phases of Interface testing in an Interface Life-Cycle, We mentioned below:-

1) Configuration and Development

When the interface configures, and once the development starts, configurations need to be verified as per the requirement.

2) Validation

In this process, the interface needs to validate and verify, this can do as a part of unit testing also.

3) Maintenance

The maintenance process starts once the whole software is ready, deployed, and working, then the interface needs to monitor for its performance and any new issues introduced due to the changes made or deteriorating performance.

We need to make sure that we are not introducing any defects in our code and hence tests need to be run on the interface to verify that adding new code is not injecting any new defects before starting to develop an interface. It helps you to determine whether the interface is defect-free and as per the requirement.

After being satisfied with the interface, we validate it for the intended workflow, data, etc. We will run performance huge data tests and check how well the interface responds which will save a lot of time that will be spent on fixing the defects later.

Types of Interface Testing

It is basically done on the messaging layer of the system architecture and during Interface Testing various types of testing are done on the interface which may include.

  • Unit Testing

We Test the functionality of each individual operation (in a function).

  • Functional Testing

Testing the functionality of broader scenarios involving test case creation, validation, regression, etc.

  • Load Testing

Validating the performance under load by using functional test cases.

  • Security Testing

It tests the security mechanism and includes penetration testing as well as validating access control, encryption, etc.

  • Runtime Error Detection

Monitoring an application for problems like runtime race, resource leak, etc.

  • Workflow Testing

It is done to make sure that the interface engine handles the workflow well and handles your workflow as expected.

  • Individual Systems

This testing is done to verify the individuality of each system such as the billing system and inventory management system should be able to operate individually.

Read Also:- Best Test Automation Tools 2023

Strategy, Approach, or Purpose for Interface Testing

Interface testing becomes more important when we verify the application’s dependencies with other apps just like any other testing. It is equally important as it ensures seamless functioning, performance, and various data-driven applications and systems, by verifying the communication between the database, networks, and systems.

Steps that Ensure Interface Testing is Successful

Below we shared 05 steps that will help you to ensure the success of interface testing.

1) Define your Requirement

It is essential to understand the application before creating Interface tests. Here we try to find answers to questions like what is the purpose of the interface? What is the workflow of the system or application? What is the function and feature of the interface?

Defining all such answers will help you to understand the requirement, find out tricky points of the application and then create the test cases accordingly. If QAs miss this, later on, this leads to confusion about the requirement or incorrect testing.

2) Expected Output

Now we understand the requirement very well we need to finalize the output that we will be expecting from the tests. It is not just a Pass or Fail, it can be some data, a call to another API, etc. It is not only tricky but also risky to measure the outcome of the expected result.

3) Start Small

Through interface testing, we can’t directly move on to creating big test cases, creating small test cases or calls is relatively simple. First, create a small test code and verify if the output is as expected or not.

4) Try Automating

It is boring to write codes for testing an interface.

You are not spending time writing the code but along with this, you will also have to spend time understanding the format, style, the coding language used for development, and then as icing on the cake you will have to make sure that your code isn’t creating a problem to the app or system code. You need to research and find some automation tools which will save your day. 

5) Define the Start and Stop Points

Before starting the execution of a test, we need to decide the start (entry) and the stop (exit) point of the test, as well as decide how the entire testing process will start and end. Similarly, we also need to measure the performance level of the Interface testing as well.

Interface Testing Tools

The best method to perform interface testing is to use automation and include interface testing in your automation plan. Hence the following list of interface testing tools will help you to complete your interface testing as quickly as possible. However, I would personally recommend using SoapUI for web application testing services but every requirement is different hence let us take a look at the 5 best tools.

1) REST-Assured

REST – Assured the most preferr tool for people working with Java. It is the best tool for API testing with Java which can easily integrate with any Java-based framework.

2) Postman

A postman is a good option for automation who doesn’t like to use the same coding language as the IDE. It has a native version available that can use for Mac, Linux, and Windows. 

3) SoapUI

SoapUI can be a great choice if your team is doing only API testing. SoapUI is a complete functional testing tool devoted to API testing. It supports Data-driven testing where the data can pass in CSV or Excel format.

4) JMeter

JMeter tool widely uses for load testing and it can use as an interface testing tool that has record & playback support it generates HTML reports which are easy to read and understand. It is also compatible with CSV files that allow you to create unique parameters for testing.

5) Fiddler

Fiddler helps you to debug website issues, by using extensions you can do much more. It helps you to check and use (again) the HTTP requests. If you need more intense on it so you can try using the FiddlerCore.Net library to create your interface testing infrastructure.

Recommended to Read – A Brief Guide On Types of Software Testing


  1. What is meant by interface testing?

An interface test is a type of software test that checks for proper communication between two different software systems. An interface is a connection that unites two components. The interface can be anything from an API to a web service.

  1. What types of interface testing are there?

The two common components of an interface test are:

  • Web server
  • Application server interfaces
  1. What is interface testing in manual testing?

An interface test is a software test used to verify the correct connection between two independent software systems. An interface is a link that connects two components. In the world of computers, this interface can be anything from an API to a web service.

  1. Why is interface testing important?

UI tests verify how your application handles user actions using input devices such as the keyboard or mouse, and those visual elements work and display correctly. It also ensures the efficient and accurate performance of software application user interface and enables quick and proper deployment to end users.

  1. What components use in interface testing?

Interface testing defines as a type of software testing that verifies that the communication between two different software systems performs correctly. A connection that unites two components calls an interface. This interface in the computer world does not matter if it is an API or a web service.

  1. What is the difference between interface testing and integration testing?

Interface tests are used to test interfaces to verify expected results. Run integration tests to verify the end-to-end functionality of your integration components.

  1. How do you write test cases for interface testing?
  • Keep it simple and transparent
  • Test cases can reuse
  • Maintain a unique test case ID
  • Peer review is important
  • Test cases should consider end users or defined requirements
  • Specify expected results and assumptions.

If you are interested in even more software testing-related articles and information from us here at Devstringx, then we have a lot to choose from.

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