Types of Software Testing

Types of Software Testing

What is Software Testing?

The role of software developers and engineers includes performing various tasks to optimise software applications. One such key task is software testing. But what is software testing? It is a process through which the developers check the functionality of a software application. Simply put, it is the process of testing the various aspects of an application to verify that it works as intended. Based on what is to be tested there can be different types of testing in software that are conducted. 

Types of Software Testing

Software companies often expect aspiring software developers and engineers to be aware of what software testing is and the different types of testing in software testing that are performed to test a product or application. Some companies hire engineering graduates as software testers to perform software testing for applications and products. There are multiple types of testing in software testing, each with its own objective and process. To give you a clearer picture, let us go through the different types of testing in software testing. 

1. Manual Testing

As the name suggests, manual testing entails testing a software product manually by the software developers or testers for bugs, defects or malfunctions.

Every team has to rely on manual testing to be able to automate a specific testing scenario. The tester has to write test cases in order to check whether the application or product is functioning as it is meant to. For manual testing, the tester doesn’t need to know programming languages. All applications can and should be tested manually. 

2. Automation Testing

You might have probably guessed it already. Automation testing is well, automated. That means that it uses tools, frameworks and scripts to perform tests that have been run through manual testing before. Tests that are repetitive, can be automated by writing test scripts or using testing tools. This reduces the need for manual testing, thus reducing redundancy and saving time. Automotive testing is used mostly for stable systems. Since test scripts are to be written, the tester should be well-versed in programming languages like Java and Python. 

3. Functional /Component Testing

Functional testing falls under black-box testing – a type of testing in software engineering that testers carry out while staying unaware of the coding logic of the application. It includes comparing the actual output values of an application’s components against the set output values provided by the tester. Under this testing, the tester is mainly concerned about the performance of the application, and hence, does not test the system.

Functional testing is another type of testing that verifies whether or not a software application functions as expected. It verifies each function of a software application by inputting relevant values and gauging its output at that instant against the expected output. It can be done either manually or through automation testing. Functional testing primarily verifies the functionalities of APIs, UI, Security applications, etc.

4. Non-Functional Testing

Non-functional testing tests the user experience of the application or product. It tests aspects that are not tested under functional testing like performance, reliability, accessibility, UX etc. 

Performance testing, load testing, security testing, portability testing, accountability testing, and efficiency testing all fall under non-functional testing. Non-functional testing helps to improve the performance of the product or application.

5. White-Box Testing

White box testing is also called clear box testing, glass box testing, open box testing or transparent box testing. It falls under functional testing and manual testing. In white-box testing, the code should be visible to the tester. The tester tests the internal structure of the software product to check the input-output flow.

Under white-box testing, the tester is concerned about the internal workings of the application and thus performs inner testing. 

The tester usually looks out for internal security gaps/loopholes, the flow of input-output, broken structured paths, and testing of each function, object and statement. 

6. Black Box Testing

If White-box testing is one side of a coin then black-box testing is the other side of the same coin. While the white-box testing method tests the inner workings of an application, black-box testing tests the product from an external perspective, that is from the end user’s perspective. Black–box testing is also a type of functional testing and falls under manual testing.

The tester runs the tests to determine whether or not the application meets the set requirements of the customer without knowing the code or the functionality of the software. Since the knowledge about the internal working of the system is not known, the test method is called black-box testing. 

7. Grey Box Testing

Combine black and white, what do we get? Grey-box testing refers to the type of testing in software testing in which the product or application is tested with limited knowledge of the inner workings of the application to verify whether or not the product meets the set requirements from a user’s perspective. Grey-box testing also falls under manual testing. 

Grey testing is usually conducted by developers and testers to test and rectify at the same time, thus saving time. Since the process is semi-transparent, it is called grey-box testing. 

8. Unit Testing

An application consists of several modules, each consisting of hundreds of lines of code. The smallest testable module or component of an application is called a unit. And to test the functionality of one unit is called unit testing.

Unit testing falls under both functional testing as well as white-box testing and helps the team to confirm whether an individual unit of the application works in the way it is intended to. 

9. Integration Testing

A type of functional testing, integration testing is followed after unit testing. You might have probably guessed what integration testing does. Integration testing is the process of testing the software after merging individual software modules or units. 

In other words, after you have checked the individual units of an application for their functionality, it is time to determine whether all the units or several units work together as they should. Thus, integration testing determines whether all the wheels are functioning together or not. 

10. System Testing 

A type of functional testing system testing is conducted after integration testing. Since it is conducted after integration testing, it is conducted on a system that is completely integrated.

It ensures that the system works as a whole and validates the system end-to-end. System testing is a type of black-box testing meaning the tester tests the application from an end user’s perspective. 

11. Performance Testing

A type of non-functional testing, performance testing relates to the performance of the application or product in terms of responsiveness, stability, scalability and load management. The test is conducted by making the application subject to a certain amount of workload. 

12. Stress Testing

In our lives, the point at which we get stressed is often the one that comes after we have been subject to a magnitude of load or mental pressure that exceeds the upper limit. Similarly, to test how an application performs under significant stress or workload, stress testing is performed.  

The tester puts stress on the application by adding heavy input values to see how the system performs and when it stops functioning. Just like performance testing, stress testing is also a type of non-functional testing. 

13. Regression testing

In regression testing, the entire application that has been tested thoroughly once is retested after a modification, such as after integrating a new piece of code into its source.

Regression testing includes running functional as well as non-functional tests to determine whether the change affects the functioning or performance of the application. 

In cases where it does not perform similarly to the performance of the application before the modification, it is called regression. Regression testing falls under functional testing. 

14. Gorilla Testing or Adhoc Testing

Gorilla testing or Monkey testing refers to testing how the application performs when random input values are entered repeatedly. The tester need not know the entire internal knowledge of the system for this. Also, the testing process does not follow a structured approach and is without adequate documentation.

Buddy testing, pair testing and monkey testing are some of the forms of Adhoc testing. 

15. Usability/UX Testing

UX testing is a type of non-functional testing. Usability testing also called User Experience (UX) testing, is used to test whether the application or product is user-friendly or not. 

User experience primarily refers to the feel, ease of use and navigation of the product as experienced by the end-user. It also takes into account whether the user can easily understand the application or not. 

16. Load Testing 

Load testing tests the maximum workload an application or product can take without malfunctioning. It also falls under non-functional testing.

Load testing helps the tester determine how the application functions under the normal workload and excessive workload. 

17. Compatibility Testing

Another type of non-functional testing, compatibility testing verifies the compatibility of the application or product with different computing environments. 

The testing team verifies whether or not the application is functional on different operating software(Windows, Mac OS and Linux), hardware (storage capacity, graphic cards, processors, etc.), networks, mobile environments (iOS, Android) and browsers (Google Chrome, Safari, Firefox, etc.).

18. User Acceptance Testing

This is usually the last step before the product is accepted by the client. It is usually performed after system, functional and regression testing. In user acceptance testing or simply acceptance testing, the client is the tester. User acceptance testing is a type of functional testing since we are testing the functionality of the product or application. The client tests the product or application to determine whether or not the application works as they want it to. 

Based on the performance of the application the customer or client can accept or not accept the application.Hence the name acceptance testing.  

Key Takeaways

If you look at the different types of testing, they usually follow a pattern. So if you ever get confused about what a particular type of software testing does, simply try to guess it from the name and follow the logical sequence. 

To quickly go over the most common types of software testing, they are-

  • Automation testing
  • Manual testing
  • Functional testing
  • Non-functional testing
  • White-box testing
  • Black-box testing
  • Grey-box testing


There are various types of software testing methods that are conducted by the development team to test out the overall functionality of a software application. The above list has some of the most common types of software testing that a software tester or engineer is likely to come across.

The difference between these types of software testing is largely attributed to the different objectives, environments, testers and processes of each of these software testing types. Despite these differences, the premise of software testing, that is, to check whether all the code written works the way it is supposed, remains key in all the types. 

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