The Difference Between Functional and Non-Functional TestingTesting is important to determining if your applications are performing like you intended them to. Two of the major categories of tests on the market are functional and non-functional testing. But what are the differences between these two tests?

Functional Testing

Before going into the differences, we should define what each are. Functional testing involves testing the application against the business requirements. The goal of functional testing is to verify that the application is behaving the way it was designed to.

Functional testing ensures that your software is ready to for release to the public. It also verifies that all the specified requirements have been incorporated.

There are two major categories of functional testing: positive and negative functional testing. Positive functional testing involves inputting valid inputs to see how the application responds to these and also testing to determine if outputs are correct. Negative functional testing involves using different invalid inputs, unanticipated operating conditions and other invalid operations.

Non-functional Testing

While functional testing is concerned about business requirements, non-functional testing is designed to figure out if your product will provide a good user experience. For example, non-functional tests are used to determine how fast the product responds to a request or how long it takes to do an action. Examples of non-functional tests include:

What’s the Difference?

The major difference between functional and non-functional testing is this: Functional testing ensures that your product meets customer and business requirements, and doesn’t have any major bugs. On the other hand, non-functional testing wants to see if the product stands up to customer expectations.

Basically, functional testing is designed to determine that the application’s features and operations perform the way they should. Non-functional testing wants to know that the product “behaves” correctly.

Your application needs to pass both categories of testing to ensure that your consumers have a good experience with your product. Failure to release a working product that meets the needs of consumer demands can damage your company’s reputation and reduce overall product sales.