Grey Box Testing Tutorial for Beginners

Grey Box testing is a software testing technique that is performed with less information about the internal functionality of the program or the code. Grey Box testers have access to the blueprint documents along with some other requirements. Grey Box tests are based on the state-based models, UML Diagrams, or architecture diagrams of the system.

Grey Box Testing

For example, during testing of websites that contain links, if an error occurs while clicking the link. The white box testing is carried by the user by altering the code and black-box testing by testing on the front end.

Steps to Initiate White Box Testing

  • Select and identify inputs from BlackBox and WhiteBox testing inputs.
  • Identify outputs from the selected inputs.
  • Identify all the major paths to cross through during the testing period.
  • Identify sub-functions in order to perform deep level testing.
  • Identify inputs for subfunctions.
  • Identify outputs for subfunctions.
  • Execute a test case for Subfunctions.
  • Verify the correctness of the result.

Grey Box Testing Techniques

Following are the Grey-box Testing techniques:

  • Matrix Testing
  • Regression Testing
  • Orthogonal Array Testing
  • Pattern Testing

Now let’s discuss it in detail.

  • Matrix Testing: It defines all the used variables of a particular program. Variables are the elements through which values can travel inside the program. The matrix technique is a method to remove unused and uninitialized variables by identifying used variables from the program.
  • Regression Testing: Regression testing is used to verify modifications in the software that can cause any unintended side effects in any other part of the software. Regression testing takes care of these types of defects by testing strategies like retest risky use cases, retest within a firewall, retest all, etc. 
  • Orthogonal Array Testing: The purpose of Orthogonal array testing is to cover maximum code with minimum test cases. Test cases are designed to cover maximum code as well as GUI functions with a smaller number of test cases. 
  • Pattern Testing: Pattern testing is applicable to the types of software that are developed by the same pattern as previous software. Pattern testing determines the reasons for the failure so they can be fixed in the next software.

Levels Applicable To Grey Box Testing

Grey box testing is applicable to only one level and it is Integration testing. A level of testing where units are tested as a group. The main aim is to expose faults between integrated units. It is the second level of testing performed after unit testing and before system testing.


  • Selenium
  • Appium
  • Rational Functional Tester
  • Chrome DevTools

Let’s discuss them in detail.

  • Selenium: It is an open-source UI automation test suite. It can be easily deployed on platforms such as Macintosh, Windows, Linux, and much more. 
  • Appium: Appium is essentially a companion to Selenium. It supports mobile apps and is cross-platform – both iOS and Android.
  • Rational Functional Tester: It is proprietary software and is owned by IBM. It supports a range of technologies, from web-based to iSeries and zSeries, at a basic level.
  • Chrome DevTools: It provides web authoring and debugging tools that will help you to resolve layout issues and improves optimization of your code to work with Chrome.

Pros and Cons Of Grey Box Testing

Offer benefits of both White box and Black box testing.Not suited for algorithm testing.
Testing is performed from the user’s point of view.It is impossible to test every input stream.
Testers depend on functional specifications instead of source code.Test coverage is limited
Testing is done on the basis of data flow diagrams.It is not suitable for distributed systems.

Difference Between Grey Box and White Box Testing

Grey Box TestingWhite Box Testing
Limited knowledge of the testerThe internal structure of the software code is known to the tester.
Also known as translucent testingAlso known as glass box testing, clear box testing, structural testing.
The testing space of tables for inputs is smaller than Black Box and White Box testing.The testing space of tables forinputs is less as compared to BlackBox testing.
Difficult to discover the hidden errorIt is simple to discover hidden errors
It is not considered for algorithm testing.Well suitable and recommended for algorithm testing.
Test cases can be designed in a short time period.It takes more time to design test cases because of the lengthy code.
Tester, developer and the usercan be the part of testing.Only testers and developers can be a part of testing; the end-user can not be involved.

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