Black Box Testing Vs. White Box Testing- What’s the Difference?

Software TestingAutomation TestingTesting Tools

Black Box Testing

A tester doing black-box testing has no knowledge of the software system's internal workings. Black box testing is a kind of advanced testing that focuses on the software's behavior. It entails testing from the outside or from the point of view of the end-user. Black box testing may be used at all levels of software testing, including unit, integration, system, and acceptability testing.

White Box Testing

White-box testing is a kind of testing that examines the system's internal workings. Testing is based on the coverage of code statements, branches, pathways, or conditions in this approach. Low-level testing is referred to as white-box testing. Glass box, transparent box, clear box, and codebase testing are all terms used to describe this kind of testing. The white-box testing approach presumes that a unit's or program's logic route is understood.

What is Black Box Testing and How Does It Work?

The processes for doing any sort of Black Box Testing are shown below

  • The system's needs and specs are assessed first.

  • To see whether SUT handles valid inputs successfully, the tester selects legitimate inputs (positive test scenario). In addition, certain faulty inputs are generated (negative test scenario) to ensure that the SUT can identify them.

  • For each of those inputs, the tester calculates predicted outcomes.

  • With the chosen inputs, the software tester creates test cases.

  • The test cases are carried out.

  • The genuine results are compared to the predicted outputs by the software tester.

  • If there are any flaws, they are corrected and rechecked.

Black Box Testing Types

There are many different forms of Black Box Testing, however, the ones listed here are the most common

  • Functional testing- This form of black-box testing is concerned with a system's functional requirements and is carried out by software testers.

  • Non-functional testing- This sort of black-box testing is concerned with non-functional criteria such as performance, scalability, and usability rather than particular functionality.

  • Regression testing is performed after code changes, upgrades, or other system maintenance to ensure that the new code does not harm the current code.

Methods for Black Box Testing

Among the various test strategies used in black-box testing, the following are the most popular −

  • Equivalence Class Testing − is a technique for reducing the number of potential test cases to the bare minimum while maintaining adequate test coverage.

  • Boundary Value Testing − Boundary value testing is concerned with the values found at the edges of a boundary. This method assesses whether or not a set of values is acceptable to the system. It's a great way to cut down on the number of test cases. It's best for systems with inputs that fall between certain ranges.

  • Decision Table Testing − A decision table is a matrix that contains the causes and consequences of a problem. Each column has a different combination.

What is White Box Testing and How Does It Work?

White Box Testing is a software examining approach that involves testing the product's underlying structure, architecture, and code in order to validate input-output flow and enhance the design, usability, and security. White box testing is also known as Clear box testing, Open box testing, transparent box testing, Code-based testing, and Glass box testing since the code is visible to the testers.

In White Box Testing, what do you check?

White box testing entails putting the software code to the test for the following −

  • Internal flaws in security

  • Paths in the coding process that are broken or poorly organized

  • The path is taken by specified inputs through the program.

  • Expected results

  • Conditional loops are useful in a variety of situations.

  • Individualized testing of each statement, object, and function

Software development might include testing at the system, integration, and unit levels. One of the primary aims of white-box testing is to ensure that an application's operating flow is correct. It entails comparing a set of predetermined inputs to anticipated or desired outputs, with the goal of identifying bugs when one of the inputs fails to provide the intended outcome.

Difference between Black Box and White Box Testing

The primary distinction between White Box and Black Box Testing is as follows −

  • Black Box testing is performed without knowledge of the program's or application's internal structure, while White Box testing is performed with knowledge of the program's or application's internal structure.

  • When comparing Blackbox and Whitebox testing, the Black Box test does not need programming skills, but the White Box exam does.

  • The primary purpose of Black Box testing is to evaluate the behavior of software, while the primary goal of White Box testing is to test the system's underlying functioning.

  • When comparing Black Box and White Box testing, Black Box testing is more concerned with the external or end-user viewpoint, while White Box testing is more concerned with the code structure, conditions, pathways, and branching.

  • The Black Box test generates results with low granularity, while the White Box test generates reports with great detail.

  • When comparing Black box testing to White box testing, Black box testing takes less time, whilst White box testing takes more time.

ParameterBlack Box testingWhite Box testing
DefinitionIt is a testing method that is used to test software without having knowledge of the program or application's underlying structure.It's a testing method in which the tester is aware of the system's internal structure.
AliasData-driven, box testing, data-, and functional testing are some of the other names for it.Structural testing is also known as clear box testing, code-based testing, or glass box testing.
Base of TestingTesting is dependent on external assumptions, and the application's underlying behavior is unknown.Because the internal workings of the system are understood, the tester may test appropriately.
UsageThis sort of testing is best suited for higher-level testing such as System Testing and Acceptance Testing.Testing is better suited to lower-level testing such as Unit and Integration testing.
Programming knowledgeKnowledge of programming is not required to execute Black Box testing.White Box testing requires a working grasp of programming.
Implementation knowledgeImplementation expertise does not need Black Box testing.WhiteBox testing requires thorough knowledge.
AutomationBecause the test and programmer are so intertwined, automating them is difficult.It's simple to automate white box testing.
ObjectiveThe major goal of this testing is to determine what functionality of the system is being tested.The fundamental goal of White Box testing is to ensure that the code is of high quality.
The basis for test casesTesting may begin when the requirement specification paper has been prepared.After completing the Detail design document, testing may begin.
Tested byThe end-user, the developer, and the tester.Typically, testers and developers are in charge of this.
GranularityThere is a lack of granularity.The degree of granularity is considerable.
Testing methodThe process of testing is based on trial and error.It is possible to test the data domain and internal bounds.
TimeIt takes less time and is less exhausting.It's a time-consuming and exhausting process.
Algorithm testThis isn't the greatest way for testing algorithms.It's ideal for testing algorithms.
Code AccessAccess to the source code isn't necessary for Black Box Testing.Code access is required for white box testing. If testing is outsourced, the code might be stolen as a result.
BenefitSuitable and efficient for lengthy code portions.It enables the removal of superfluous lines of code that may introduce hidden flaws.
Skill levelLow-skilled testers may test the application without having any prior understanding of the programming language or operating system.To execute white box testing, you'll need an experienced tester with a lot of expertise.
TechniquesEquivalence partitioning is a Black box testing approach that is used in Blackbox testing.
Equivalence partitioning separates input values into valid and invalid divisions, then selects equivalent values from each test data partition.
Analysis of boundary values Input values is checked for bounds.
White Box testing techniques include Statement Coverage, Branch Coverage, and Path Coverage.
Statement Coverage checks to see whether each line of code is run at least once.
Whether each branch is performed at least once is determined by branch coverage.
The path coverage approach examines all of the program's pathways.
DrawbacksIf you constantly change your application, you'll need to update your automation test script.If the code base is quickly evolving, automated test cases may become obsolete.


As a result, both white box and black box testing are necessary for software delivery to be effective. However, in both circumstances, 100% testing is not achievable. The primary responsibility of the tester is to uncover as many problems as possible in order to enhance the application's efficiency. Both black box and white box testing are used to ensure that a program is functioning properly.

As a result, both testing approaches must be understood. It would also be beneficial to understand the differences between the two terminologies in order to choose the best alternative.

Updated on 25-Nov-2021 07:04:52