What Is Regression Testing? Definition, Tools, Method, And Example

Nov 28




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Regression testing is re-running functional and non-functional tests to ensure that previously developed and tested software still performs after a change. If not, that would be called a regression.


Regression testing is considered to be a kind of testing which is done for verifying that any changes in the code of the software does not have any negative effect on the existing functionality of the product.

This is done for ensuring that the software is working properly with the latest functionalities,What Is Regression Testing? Definition, Tools, Method, And Example Articles bug fixes or for introducing any changes in the existing feature. Test cases which were previously executed are re-executed for verifying the effect of the change.

What is regression testing?

Regression testing is similar to a verification process. Here, test cases are known to be automated as it is essential to execute and run the test cases time and again manually. Executing and running the test cases manually is a tedious process and consume a lot of time.

Few problems may occur in the confirmation email and certain changes in the code are done for fixing the same. It is a prerequisite to test the confirmation emails in such cases. It is necessary to test the Dispatched and Acceptance emails for ensuring that if any changes have been introduce in the code, it has not lead to any bugs or errors.

Automated regression testing tools

Automated regression test is recognized to be the testing area in which majority of the testing efforts are automated. Here, all the test cases which have been executed previously are run on a new build. Running and executing the test cases manually consume a lot of time.

 Automation of the test cases save a lot of time and thus it is regarded as an effective regression testing technique. The extent of the automation relies on the total count of test cases which are going to be application over the due course of time.

If the test cases differ from one time to the other, the application scope enhances and thus the automation of regression becomes a time waste. Majority of the regression test tools, available in the market, are known to be playback and record type. The test cases are recorded by the navigation via AUT and verifying if the expected results are going to come or not.

Ranorex Studio

With this powerful regression tool, it is possible to maximize the resources and improve the quality of the software. You will be capable of executing more test cases in no time by using this tool. Thus, you can get an increase of 78% efficiency over manual testing by using this tool.

Katalon Studio

Katalon Studio is recognized to be an all-in-one automation tool for the desktop, API, website and mobile apps. By using this tool, you will gain success in designing as well as automating the test cases in no time.

It also allows you to run the scripts on a plethora of cross browsers devices in parallel. In addition to this, it also helps you in reviewing the test results along with a customized and comprehensive test report in CSV, HTML, Logs, and PDF formats and forwards the same in the email attachments via the Katalon Studio.

Other tools include Regression Tester, AdventNet QEngine, Selenium, Watir, vTest, TimeShiftX, SilkTest, Rational Functional Tester, etc. Updating and addition of regression test cases in the automation test suite happens to be tedious task. While choosing the automation tools for the regression tests, you need to check whether the tool enables you to update or add the test cases without any hassles.

Types of Regression testing

Few of the methods of regression testing include partial regression, unit regression and complete regression.

Unit Regression

Unit Regression is accomplished during Unit testing stage whereas the testing of the code is done in isolation. Any dependencies of the unit which can be tested needs to be blocked so that it is possible to test the units individually without any sort of discrepancy.

Partial regression

Partial Regression is known to be done for verifying that the code is working fine even when changes are introduced in the code or if the unit is integrated with the already existing and unchanged code.

Complete regression

Complete regression is done as any code change is accomplished on the number of modules and whether the effect of change in any part of the module is not certain. Thus, the product is regressed as a whole for checking whether any flaws have been introduced owing to the changed code.

Regression Testing Techniques

Here is a list of the leading regression testing processes.

Retesting all

The whole test cases in the test suite are known to be re-executed for ensuring that no errors have been introduced if any change has been made in the code. It is considered to be an expensive technique as it needs more resources and time, in comparison to the other procedure.
Regression Test Selection

In this technique, the test cases which are chosen from the test suite needs to be re-executed. Here, not the whole product is re-executed. Choice of the test cases is accomplished on the basis of change in the code in the module. The test cases are known to be divided into two categories, the Reusable test cases and the obsolete test cases.

Test case prioritization

Test cases, having the high priority are known to be executed at first. The priority of these test cases is dependent on the cruciality as well as its effect on the product, and its functionality.


The hybrid process is considered to be the combination of test case prioritization and regression test selection. Instead of choosing the whole test suite, you need to choose only those test cases which can be re-executed, according to the priority.

Regression testing services is considered to be a kind of software testing in which every test case is re-executed for finding if the previous functionality of the software is working properly and whether the latest changes have not lead to any errors in the product.

It is possible to perform the test on a new build as significant change is introduced in the original functionality. Regression refers to the retesting of different unchanged parts of the software.