What is Regression Testing? Definition, Tools and How to Begin


What is Regression Testing? Definition, Tools and How to Begin


What is regression testing?

Regression testing is software testing that ensures that an application continues to perform as expected after any code changes, updates, or upgrades.

Regression test is in charge of ensuring the general stability and functionality of current features. It is used whenever a new modification is added to the code to ensure that the system is sustainable under continual improvement after each update.

Code changes may introduce dependencies, flaws, or malfunctions. Regression test seeks to mitigate these risks by ensuring that previously produced and tested code continues to function after new changes.

Generally, an application is subjected to several tests before the modifications are incorporated into the main development branch. The final step is regression test, which validates the overall product behavior.

When should regression testing be used?

Regression test is typically used in the following situations:

  • A new requirement is added to an existing feature.
  • A new feature or functionality is added.
  • The codebase is fixed to solve defects.
  • The source code is optimized to improve performance.
  • Patch fixes are added.
  • Changes in configuration

Why is regression testing important?

Test automation is an essential component of software development techniques. Similarly, automated regression test is seen as an important puzzle piece.

Product teams can receive more informative feedback and respond quickly with a rapid regression testing methodology. It detects new flaws early in the deployment cycle, saving firms money and time spent on maintenance to correct built-up defects. A seemingly little change can sometimes have a cascading effect on the product’s major functionality.

That is why developers and testers must not leave any change outside their control scope, no matter how minor.

Functional tests solely examine the behaviours of new features and capabilities while ignoring their compatibility with current ones. As a result, it is more difficult and time consuming to analyze the root cause and product architecture without regression test.

In other words, if your product is frequently modified, regression test will serve as a filter to assure quality as the product improves.

How to Conduct Regression Testing

Organizational strategies for regression testing differ. However, there are a few fundamental measures to take:

Identify Source Code Changes

Detect changes and optimizations in the source code; then identify the altered components or modules and the effects on existing functionality.

Prioritize Those Changes and Product Requirements

Then, prioritize these changes and product needs to streamline the testing process with the relevant test cases and tools.

Determine Entry Point and Entry Criteria

Before running the regression test, ensure your application meets the eligibility requirements.

Identify the Exit Point

Determine an exit or final point for the eligibility or minimum conditions established in step three.

Schedule Tests

Finally, identify all test components and plan the proper execution time.

Tools for Regression Testing

Katalon Studio

Katalon Studio is an end-to-end automation tool that enables functional and regression test, making these procedures quick and simple for testers to perform.

Katalon Studio is a one-stop shop for regression testing your website, web services, and mobile applications. The program also allows scripts to execute on multiple devices, browsers, and contexts.

In-depth, you can review test results using the extensive and configurable test reports in LOG, HTML, CSV, and PDF formats and send them as email attachments.


Selenium provides a set of features for automating web applications. It is still regarded as one of the best browser-based and cross-platform regression testing tools. Selenium provides data-driven tests and automated test scripts that cycle over data sets. This is an appropriate solution for large-scale quality assurance teams of advanced testers. On the other hand, its steep learning curve becomes a challenge for small and mid-sized groups.


Watir, for Web Application Testing in Ruby, is a free and open-source library written in the Ruby programming language. It allows you to write tests that are simple to read and manage using a lightweight and adaptable user interface.

Watir enables a wide range of user interaction capabilities for website testing, including clicking links, filling out forms, and verifying text across browsers.

IBM Rational Functional Tester

IBM Rational Functional Tester, or RFT, is a software test automation tool. RFT can be used for various software testing types, such as functional, regression, GUI, and data-driven testing, as well as applications (web-based,.Net, Java, Siebel, SAP, and others).

Apache JMeter

Apache JMeter is a free, open-source test automation tool for loading functional test behaviours and measuring test performance. It has a wide range of testing capabilities, including support for load and performance tests on various apps, servers, and protocols and a full regression test suite for end users.

Read more: Automation Testing Tools – How to Choose The Right One

Regression testing techniques

The three most common implementation approaches for regression test are re-test all, regression test selection, and test case prioritization.

Retest All

Regression testing is done on all current test suites in this technique. Although it is the most secure approach to ensuring all problems are found and resolved, it takes significant time and money.

As a result, the complete regression strategy works better in certain situations, such as when the application is adapted for a new platform or language or when the operating system is updated significantly.

Regression Test Selection

You can choose the relevant portions affected by the modifications and run regression test exclusively on these areas. By focusing on the relevant regions, you may apply fewer and more applicable test cases, reducing the time and effort spent on regression test.

Test Case Prioritization 

You can prioritize the test cases that must be included and completed in the regression testing process. The following criteria should be utilized to prioritize these test cases: failure rate, business impact, and gradually used functionalities.

Test cases relating to customer-facing features and newly added functionalities are also considered.

Differences Between Re-testing and Regression Testing

For automation newcomers, the words re-testing and regression test can be perplexing. They may sound similar, yet they are pretty different.

Re-testing means “testing again” for a specific reason. Re-testing occurs when a bug in the source code is fixed or when a specific test case fails in the final execution and must be re-run.

Regression testing determines whether updates or changes produced new faults in existing functions. This step would secure the software’s unity.

Re-testing comes before regression test in a typical software development cycle. Re-testing focuses entirely on failed test cases, whereas regression test examines those that have passed to look for unanticipated new flaws. Another major distinction is that, unlike regression test, re-testing includes error verifications.

Furthermore, automation is an important aspect of regression test since it allows you to make the most of your test case capabilities. Regression test also eliminates all underlying side effects induced by code modifications in the most cost-effectively.

Regression Testing in Agile

Teams can receive several benefits and values from the Agile development strategy, including expedited time-to-market, ROI, customer support, and product upgrades. However, balancing sprint development and iterative testing to avoid conflicts as the product evolves is a huge problem.

Agile regression testing implementation is critical for synchronizing existing and upgraded capabilities and preventing future rework. Agile regression test ensures the stability and sustainability of business functions.

In addition, regression test allows developers to focus on developing new features for the application rather than returning to check for problems in existing features. Regression test identifies unanticipated hazards in software builds, allowing developers to respond more swiftly and efficiently.


Regression testing is critical for improving overall product quality and user experience. The correct regression testing tools can considerably uncover and eliminate all surfaced faults early in the pipeline.

Furthermore, regression testing in Agile provides a slew of technical and financial benefits. As a result, the more your organization invests in planning and implementing regression testi, the more control you will have over your product’s budget, process, and mistake mitigation.

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