Difference Between Black Box and White Box Testing

Explore The Difference Between Black Box and White Box Testing

Software Testing plays an integral part in the development process. It ensures the excellent working of the software, without any errors, bugs, and complements user experience. If any of these parameters remain unchecked and released in the market without prior evaluation, it may put the creator in a risky situation. No client would entertain poorly functioning software. Thus, to find a way from all these blunders, it is best to opt for software testing, which contains various methods. Among them, the most popular is Black Box Testing vs White Box Testing. Though they are popular, choosing between the both is equally confusing as there is an immense difference between black box and white box testing.

So, to brush off this confusion, we are highlighting the key difference between black box and white box testing. Software testing may absorb a great deal of time and investment, but it is worth every penny and second. If incorporated from the project initiation, it will save time by discovering the bugs at the early stage and curtail last-minute code refurbishment. Without any further ado, let’s get going about black box vs. white box testing.

Black Box Testing vs White Box Testing


What is Black Box Testing?

In Black-box testing, a tester does not know the internal structure of the software system. The application tested is like a black box, which cannot be seen internally. In simple words, testers do not worry about the technology used or the functions implemented. They focus on whether the app satiates all the requirements from the end-users perspective. Besides, testers also evaluate each feature of the software to ensure they are performing the assigned tasks.

Amid this, there are various types of black-box testing:

1. Functional Testing

When a particular feature or function is tested, then it comes under black-box testing. For example, a correct password helps to log in, whereas an incorrect password leads to failure.

2. Non-functional Testing

If functional testing revolves around functions, then non-functional testing is all about non-functional requirements. It involves the testing of more facets than functionalities. It also evaluates the working of the system, like, is worth it when there is the maximum load, compatibility across devices, and ease of usage.

3. Regression Testing

This type of black-box testing runs recurring functional and non-functional tests to ensure that the developed software performs well despite changes. In simple words, it confirms whether the new codes affect the efficacy of old ones. If they do, then it would be called a regression.

Apart from these, there are black-box testing techniques too, like:

4. Decision Table Technique

This technique relies on an organized approach. It consists of capturing varied input amalgamation and their system behavior in a table format.

5. Boundary Value Technique

This technique primarily tests boundary values, which consist of an upper and lower limit of a variable. While entering the boundary value, it determines whether the software is producing an apt output or not.

6. Cause-Effect Technique

In this technique, there is an evaluation of the affiliation between a given result and the factors affecting the result. It relies on the collection of requirements.

What is White Box Testing?

If black box testing is all about the external structure, then white box testing is all about internal. In this type of testing, the testers must possess extensive knowledge of the application’s internal code structure. Furthermore, they have to keep a close eye on the overall functioning of the app and ensure its appropriate functionality.

As compared to black-box testing, this testing is undertaken at an initial stage by experts who have worked on the code, like developers or technical engineers. These experts are thoroughly aware of the internal structure, technologies and are well-versed with the serviceability of each function. Their inputs for conducting the tests are based on the information gathered from the app’s internal design and structure. With this, it becomes easy to determine the results when fed with a variety of inputs.

Just like black-box testing, there are various types of white-box testing too.

1. Unit Testing

This type of testing is the initial part of testing. Complementing the name, unit testing evaluates a single unit and finds the defects in it. Whatever code is developed, the developers ensure to make it bug-free. 

2. Path testing

Path testing consists of writing the flow graphs and testing all independent paths. These graphs represent the flow of the program and how the program is correlated with each other.

3. Loop testing

As the name suggests, loop testing is all about focusing on the loops like while, for, and do-while, etc. This type of white box testing validates the loops while controlling the structure.

4. Testing for memory leaks

Memory leaks are an unfortunate scene that takes away the credibility of the code. It further slows down the process, which is why the tester examines the code to determine the actual leak point.

Just like black-box testing, there are white box testing techniques too.

5. Data flow testing

In this white box testing technique, there is a group of testing strategies to evaluate the control flow of programs. It is undertaken to investigate the sequence of variables as per the sequence of events.

6. Branch testing

This technique includes all branches of the control flow graph and covers all probable outcomes of each condition at least once.

7. Statement testing

This technique is primarily used to design white box test cases. Besides, it also includes the execution of all statements of the source code at least once.

8. Control flow testing

Determining the execution order of statements or instructions of the program amid control structure is what this technique is all about. The program’s control structure is useful in developing a test case.

Now we know the terminologies, types, and techniques of black-box testing vs. white box testing. We hope the basics are now clear. Before we jump to the conclusion, let’s sum up the key disparities.

Crucial Differences Between Black Box and White Box Testing


  1. For white box testing, if a tester requires software programming knowledge of the application, then it is the other way around in the case of black box testing. There is no need for programming knowledge for the ultimate evaluation of the application in black box testing.
  2. Code conditions, structure, and paths play a pivotal role in white box testing. Besides, black box testing emphasizes behavioral and functional properties.
  3. White box testing focuses on the internal structure of the application, whereas, black box testing can be conducted without the knowledge of the internal structure of the software application.
  4. The reports produced under white box testing are detailed and precise. However, black box testing offers low granularity test reports.
  5. As it works on external structure, black box testing is not exhaustive and time-consuming as compared to white box testing.
  6. The main objective of black box testing is to evaluate the functionality of the system, whereas white box testing is undertaken to check the quality parameters of the code.
  7. Black box testing examples include testing a login screen of software or a web application, which consists of a username and password. In the black box testing, preference is given to test the valid username and password to log in to the right account. On the other hand, when it comes to white box testing example, there are various stages, like, identifying the feature, program to be tested, noting down the path in a flowgraph, identifying all the possible paths, writing test cases for every path, and lastly executing, refurbishing and repeating till it’s perfect!

Despite the difference between black box and white box testing, these technologies are competitive and vouch for a flourishing career. But to gain utmost knowledge, it is imperative to enroll in a software testing training institute in Pune. Want to know more, keep scrolling.

Cyber Success, Best Software Testing Training Institute in Pune

If hounded with the query – “where to find the best software testing course near me?” Worry no more and choose Cyber Success for ultimate results. Gain abundant knowledge, which helps to survive the rat race. Besides, flourish your career with live projects, 100% placement assistance, mock interviews, global certification, and so much more.

So, this is the right time to skyrocket your career by choosing the best software testing training institute in Pune – Cyber Success. Carve the path of success by calling on (+91) 9168665643, (+91) 9168665644, or drop an email at hello@cybersuccess.biz.