There are many different ways to quality test your product. Most people are familiar with the basics of manual testing and automation testing, but fewer know of white box or black box testing or what the difference between them is. Which one is better for your organization's projects?

What is White Box Testing?

White box testing is a software testing technique where the application's infrastructure and source code are tested. It involves a thorough understanding of the programming behind the application and what the expected outcome of each test is.

The main focus of white box testing is ensuring that an application's code is solid and secure, and that the flow of each process is natural and user friendly. White box testing got its name from the idea of looking into an clear (or white) box. You'd be able to see the inner mechanisms and how they make the process run.

Advantages of White Box Testing

• Programming expertise: testers will be able to sift through and identify problematic bits of code, saving programmers time searching for flaws.
• Identify problems quicker: testers can utilize unit testing to test small batches of source code and locate flaws in the code much earlier in development
• Detect security issues: some white box testers are specialized in performing multiple attacks at the project's code to expose any security risks or flaws.

Disadvantages of White Box Testing

• Difficulty finding testers: only certain testers are capable of performing White Box testing, so resources are limited.
• Expense: because of the limited amount of qualified testers, cost can be a negative factor for some businesses.
• Human error: as with any other human-based testing, there is a chance that codes can be mistakenly missed.

What is Black Box Testing?

Not all projects require the quality testers to know how to code. Black box testing (also known as behavioral testing) is a software testing method that primarily works on reviewing and testing the structure, design, and implementation of the application. The test designer selects valid and invalid input and determines the correct output.

Think of it as filling out a form on a website. You should know that certain fields are required and cannot execute without content inside them. Black box testing would be like going through the form and filling out the various entry points, submitting each test to make sure all fields are correct.

Much alike how white box testing is named from the ability to "see" through the white box, black box testing is where you can't see what makes the project tick.

Advantages of Black Box Testing

• Quicker test case development: as the testers are only concerned with the GUI of the application, they do not need to dig into the code to identify process issues.
• User experience: tests are performed at a user's point of view.
• Unbiased review of project: the tester and developer are two different people. The tester does not have knowledge of the application's code, so they do not have a personal bias towards the code's functionality.

Disadvantages of Black Box Testing

• Test paths can be missed or repeated: due to the fact the programmer and tester are two different entities, test processes can be mistakenly duplicated. There is also a chance that some paths may not be identified in testing.
• Not all aspects of the application can be tested: due to the tester's lack of coding knowledge, some functions and features are unable to be reviewed.
• Requires clear and concise test specifications: if the testers don't know what they need to test, they can not provide a quality project.

Different Types of QA Testing

Alongside black box and white box testing, there are easily dozens of other kinds of software quality testing options for you to consider. Depending on your project's needs, you could utilize compatibility testing, functional testing, load testing, and everything in between.

Testing Excellence has an excellent article about the different types of software testing explaining the differences between them.