Is Unit Testing Black Box or White Box Testing Technique?

Software development is an exciting thing. It’s one of the most complex and time-consuming processes in a company, but at the end of it all, it can be worth it.

The other process that can take a lot of time, but it’s equally worth it, is testing. There are black box and white box testing techniques. And then there is unit testing.

Unit testing is a white box testing technique. White-box testing refers to a methodology that relies on the tester having full knowledge of the internal structure/design of the code being tested. Unit testing requires more effort, but it also gives the software developer a lot of benefits.

If you’re not familiar with how unit testing fits into the testing process, then this article will walk you through some basic terms so your project can benefit from unit tests.

What is unit testing?

Unit testing is a white box testing method where you check individual units of source code. Developers write those tests to check only the functionality of a small part of an application at a time.

unit testing

A unit test will often leave out the details that are not relevant to testing software functionality and demonstrate its logic by establishing preconditions, then exercising the unit and evaluating the results against expected outcomes. You can think of a unit as a “chunk” of production code that needs to be evaluated in isolation. Thus, you isolate the unit from external dependencies.

If you need to test your code with external dependencies included, you need to use black box techniques.

Unit tests target individual units in an application or component level instead of end-to-end or integration tests that target execution from start to finish. These unit tests can be executed quickly and should pass with every commit. By aggregating all passed unit tests, developers can generate insights about their code coverage and software quality and create an automated testing tool that finds bugs much earlier, thus saving both time and money spent on fixing them later.

What is the white box testing technique?

White box testing is a type of software testing which tests the internal logic of the software application. It uses knowledge about how the application works and its programming code to test for any errors.

The focus of this technique is more towards testing smaller parts of the application. Therefore, to perform a white box test, you need to have solid knowledge about programming and testing.

Developers can use white box testing to test their code to find bugs and eliminate errors before making it into production. By doing this, developers can quickly spot inconsistencies between expected outputs and actual outputs during execution time, thereby identifying possible bugs or errors in their code before they go live.

White box testing is also known as transparent box testing, glass box testing, or clear box testing.

What is the black box testing technique?

Black box testing is a testing type that tests the functionality of an application without knowledge of the internal implementation. You can use it to test all kinds of software, from desktop applications to websites and mobile apps. Black box testing tries to break your app by throwing in random input into variables, checking for error messages or crashes, and then seeing if your code caught those errors.

Black box testing is often seen as one of the most effective ways to test your app because it does not require knowledge about how or what is being tested, only that the desired behavior occurs. In addition, this type of testing helps eliminate any potential bias in case you are too familiar with specific code and know exactly what to expect when running tests.

You can perform black box test with manual testing. The testers are given specifications for desired functionality that they then try to break by inputting invalid data into the system, trying out various combinations of inputs, etc. QA testing doesn’t require any knowledge about how your system works so you can get feedback from people who might not have programming knowledge.

Many tools on the market can automate black box testing. As a result, automated testing can reduce risks associated with human error while manually checking each feature.

Black box testing is also known as functional testing.

Is unit testing a black box or white box testing technique?

Unit testing is a white box technique.

The reason for this is that you can see what the code does before it executes. This allows you to write a test case for every aspect of your code. You can then be sure that there are no errors or bugs because you can look at the source code to figure out how it works. Unit software testing method is especially valuable for algorithm testing.

There are some cases when you can use unit tests as black box testing. For example, when you have to change a legacy code, you can use characterization unit tests. The assumption here is that you can unit test your legacy code, which is often not the case. More likely you will have to use integration testing when dealing with legacy code.

Is unit testing the same as white box testing?

The short answer is no. Unit testing and white box testing are not the same things.

Unit testing is one way to perform white box testing.

Unit testing does require a thorough knowledge of your code, but it’s important to note that unit testing focuses on individual parts of your application.

The other testing that focuses on a bigger part of the code is integration testing. An integration test is a test that checks whether the different components of an application work correctly together. Since it covers a bigger part of the code and some external dependencies, some people also call it gray box testing.


In conclusion, unit testing is a white box technique. It’s one of the best ways to break down and inspect your code for bugs or other errors that might be hiding in there.

Unit tests should always come before you start refactoring because they will tell you if any changes have broken anything.

Testing can also help catch some design flaws, all without actually running the app!

All in all, making sure you test the code thoroughly should be a top priority when developing software from scratch or updating an existing application.

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