What is ‘Black box test’?
Black box testing is a type of software testing that does not involve testers in the source code of the system under test. It is usually performed by a quality assurance team and does not necessarily require advanced technical skills such as programming.
Black box testing is designed and executed with test cases based on inputs and outputs as defined in the requirements specification.
Black box testing can be used at all levels of testing. However, unit testing is left to white box testing, while black box testing is commonly used for system and acceptance testing.
Black box testing can be used for non-functional testing (performance testing, usability, accessibility, etc.) as well as functional testing.
What is ‘White box test’ ?
White box testing is a testing method that focuses on internal behavior.
White box testing is ideal for unit and integration testing.
This allows errors and defects to be identified early in the development process. Especially when working in a CI/CD environment, it is more efficient to run these tests after each deployment.
White box testing can be used to test functionality, but it can also be used to find vulnerabilities in the system. This is something that is difficult to achieve with black box testing techniques.
Black Box Testing vs. White Box Testing Comparison table
| Black Box Testing | White Box Testing |
| No understanding of the inner workings is required. | Requires a good understanding of the system’s code |
| Most often performed by QA team | Developer Execution |
| Focuses on the behavior of the system. | Focuses on the logic and the implementation of the software. |
| Test Techniques Equivalence partitioning Boundary value analysis Decision table State-transition ・ | Test Techniques Statement coverage Branch coverage Condition coverage |
| Scenarios can be run manually or with automated testing | Usually run by automated tests |
| Better suited for higher levels of testing. | Suitable for low-level testing |
| Tests from the end-users’ perspective. | Tests from a technical perspective. |
Black box testing and white box testing are two different approaches that address different needs during the development process.
White box testing is done primarily by developers and applies to low-level testing.
Black box testing is performed by the high-level QA team, but they are most effective when used together.
