Difference Between Black Box Testing and White Box Testing

This blog explain the similarities and differences between black box testing and white-box testing and their pros and cons.

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Software testing is an important part of making software. Testing ensures that software performs as intended, without mistakes or flaws that reduce the user experience. Without extensive testing and quality assurance, software put on the market might not work right or be harmful, which would be frustrating for customers and hurt the producer's brand image.

Even though testing software can take a lot of time, it is a good investment. When built into projects from the start, well-designed testing procedures save time by ensuring bugs are found early, making it less likely that a lot of code needs to be fixed at the last minute.

There are two types of software testing: white box testing and black box testing. To learn more about test types, read our blog post: What is Automation Testing? Types, Examples, Process

This blog will clarify the misunderstandings between black box testing and white-box testing, and explain the similarities and differences between the two.


What Is Black Box Testing?

In black box testing, the testers examine how an app functions without having a deep familiarity with its architecture or design. A simple comparison between the input and the result is all that's required for testing. Black box testing is also known as specification-based testing, closed box testing, or opaque box testing because of its focus on the specifications rather than the actual implementation.

The main goal of black box testing is a comprehensive look at how an application works. It is similar to behavioral testing, but behavioral testers may not know much about how an application works on the inside.

Most new software applications are tested with the black box method. It has a lot of test cases, which makes it easier to find bugs. This method of testing is used at every stage of making software.

Black box testing is about understanding how the user feels, so testers don't need to know a lot about technology to do it. It's a good way to test a lot of things, especially compared to white box testing, which can be so specific that testers miss the bigger picture.

This kind of testing happens after development is done, and the two steps are separate. 

Read Also: 7 Automated Testing Tools For Web Applications in 2023

What is White Box Testing?

In white box testing, the software's internals—including its code, design, and structure—are inspected to ensure a smooth data transition from input to output. 

White box testing improves an application's design, ease of use, and security. This method is also known as code-based testing, glass box testing, clear box testing, open box testing, transparent box testing, and open box testing.

White box testing is more intensive than black box testing, which focuses on providing a seamless user experience. Combined with other bug-fixing methods, it is a strong quality assurance tool. 

See Also: Top 20 automation testing tools.

This method is meant to run detailed simulations of all the situations an application could face at the code level.

White box testing is a good way to squash bugs because it is detailed. This testing method is open and thorough and shows what kinds of results the application could theoretically produce. White box testing is used to find errors that are hidden inside the code and to fix it.

Most of the time, QA teams put every part of an application through black-box testing. 

White box testing is usually only done on the most important parts of an application. This is because white box procedures use a lot of resources. It is used for applications like money transfers and national security, which could directly affect people's lives and therefore cannot afford to fail.

Black-Box And White-Box Testing: Pros And Cons

Pros of White Box TestingCons of White Box Testing
Can be done by development teamTime required of developers
Does not require a completed GUICode updates can invalidate test cases
Highly systematic / easy to reproduceHard to separate the program and the testing environment
Thorough – can test every possible path 
Can uncover errors early in the development process 









Pros of Black Box TestingCons of Black Box Testing
Testers need not be highly technicalUsually does not capture all scenarios / software paths
Simulates end user experienceTesting outcomes can be difficult to document and/or reproduce
Easy to create test casesTests can be redundant and time intensive
Value of external/non-developer perspectives 
Can be automated 









What Is Black Box And White Box Testing With Example?

To understand these terms better, let’s consider these examples.

Black Box Testing Example

In software testing, "black box" refers to the practice of evaluating the functionality of the application under test (AUT) without knowing how it is built. The application will be tested as if it were a black box.

Black Box Testing Technique: A testing method that creates test cases based on how the application works, without taking into account how the system is put together on the inside.

Read Also: How to Create Test Cases for Automated Tests? With Example

When testing an application without knowing the underlying technology, sometimes known as "black box testing," testers instead focus on the AUT's functionality in relation to the requirements and SRS.

In black-box testing, most of the testing will focus on what inputs could be used and what outputs are expected. A tester should know how to carefully choose the valid test data. In plain English, a tester can only see what the AUT does. The tester doesn't have to know how those things are done.

Using a television as an example, black-box testing is quite easy to understand. As TV viewers, we don't need to know how the TV is put together or how it works, etc. We just need to know how to use the remote control to switch the television on and off, change channels, adjust the volume, etc.

In this case,

  • Your AUT is your TV.
  • The user interface for testing is the remote control.
  • All you need to do is know how to use the app.

Here is another example for black box testing.

Imagine that you want to buy a new car and have done some research to find 3 options that meet your needs and fit your budget. Now, how will you compare these three choices so that you can pick the best one?

Most likely, you'll take a few test drives to figure out which one is best. Here, you are not concerned with the automobile's internal mechanisms. Instead, you make a decision based on how easy it is to use and how well it works.

White-Box Testing Example

The term "white box testing" refers to verifying a software component's functionality by examining its underlying structure.

White Box Testing Technique: A way to create and/or choose test cases based on analyzing how a component or system works on the inside.

White box testing is a way of testing that is used to check how an application is put together. The tester (or, more likely, the developer) must be familiar with the app's inner workings and architecture to carry out such tests.

Repairing an automobile engine, for instance, requires an understanding of the engine's internal construction.

In this situation,

  • The AUT is CAR (Application Under Test).
  • The tester of the black box is the user.
  • The white box tester is the mechanic.

Read Also: 5 Failures in Test Automation: Best Practices for Dealing with Them

Key Differences Between Black Box and White Box Testing


Black Box Testing

White Box Testing


A testing type which is used to test the software without the knowledge of the internal structure of application or program.

A testing method in which internal structure is known to the tester.


Box testing, data-driven, functional testing

Clear box testing, structural testing, code-based testing, glass box testing


Ideal for System Testing, Acceptance testing

Ideal for Unit Testing, Integration testing


Main goal is to check what functionality of the system under test.

Main goal is to check the quality of the code.


Less time-consuming

More time-consuming

Tested by

Tested by developer, tester and the end user.

Tested by developers and tester.

Implementation knowledge

Implementation knowledge is not required.

Implementation knowledge is required.

Programming knowledge 

Not required to perform.

Programming knowledge is required.

Basis for Test Cases

Begin once the requirement specification document is ready.

Can begin once preparing for detail design document.


Since the test and the programmer need each other, it is hard to automate.

Easy to automate.


Efficient for large code segments.

Allows you to get rid of the extra lines of code, which can lead to hidden bugs.


Trial and error method.

Data domain and internal boundary tests are possible.

Algorithm test

Not for algorithm testing

Ideal for algorithm testing

Code Access

Not required for Black Box Testing.

Requires code access. 




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