What Is Equivalence Class Testing?

Software testing is a rather interesting and sometimes even funny sphere of activity. Executing the set tasks and responsibilities, the specialists handle the plenty of terms, notions, and concepts.

The variable principles, methods, and techniques are applied by the specialists during the performance of all types of testing, for example, automated testing, functional testing, usability testing, system or module testing, and so on.

Software testing company often faces the situation when the experts apply one or another principle in their activity and even do not realize it. Everything is fulfilled intuitively, a tester does not focus on that he conducts the work with the certain technique applied. Frequently, this happens during the equivalence class testing application.


This technique is used for the equivalence tests checking. For example, the system means the presence of several informative placeholder fields. The input data may be different. The specialist is required for testing correct and incorrect data for each block.

What Underlies Equivalence Class Testing?

  • If the bug is detected with the help of one test case from the certain equivalent class, then the input of the rest of incoming data variants will throw the same error.
  • If the error is not discovered during the test case execution from one equivalent class, then there will be no errors in the other values input for this class.

The equivalence class testing significantly simplifies and accelerates the system function checking. Instead of creating a great number of test cases for each input data combination, it needs to fulfil only one test case. As the practice shows, the result will be valid for all values of this equivalence class.