What is Regression Testing and Its Types?

In the dynamic landscape of software development, change is constant. Applications are frequently modified to introduce new features, address bugs, or improve performance. However, these changes can inadvertently disrupt existing functionality, leading to broken features and poor performance. This is where the importance of regression testing comes into play. In this article, we’ll delve into the world of regression testing, exploring its significance, benefits, types, and best practices.

Understanding Regression Testing

Regression testing is a critical quality assurance practice aimed at ensuring that recent changes to an application do not negatively impact its existing functionality. This meticulous testing process helps detect and eliminate defects that might have been introduced due to modifications while preserving the overall quality of the product.

Benefits of Regression Testing

1. Early Detection of Defects: By identifying issues early in the development process, regression testing saves time, effort, and resources that would otherwise be spent on fixing these issues later.

2. Maintaining High-Quality Product: Consistently performing regression tests guarantees that the application’s quality is maintained throughout its lifecycle, fostering a positive user experience.

3. Confidence in Functionality: Regression testing instills confidence in development teams that their modifications have not broken any existing functionality.

Challenges in Regression Testing

The main challenges in regression testing are as follows:

  • Test suites grow in size as more regression runs are performed. And the whole regression test suite cannot be run due to time and financial restrictions.
  • Decreasing the test suite while attaining maximum test coverage is still difficult.
  • Determining the frequency of regression tests, such as after every modification, every build update, or after a slew of issue patches, is not so easy.

When to Perform Regression Testing

Regression testing is most effective in the following scenarios:

1. Addon Functionality: When new features are added to existing functionality.

2. Change Request Implementation: After making requested changes.

3. Bug Fixes/Performance Enhancements: To ensure that fixes or optimizations haven’t introduced new problems.

4. Environmental Changes: When the application’s environment undergoes modifications.

Best Practices for Test Case Selection

1. Bug-Prone Test Cases: Prioritize test cases that have historically revealed defects.

2. Core Functionality Cases: Include test cases that cover the application’s core functionality.

3. Integration Flow Cases: Test the flow between integrated components thoroughly.

4. Recently Changed Cases: Focus on test cases that have been recently modified.

Prioritizing Regression Test Cases

Categorize regression test cases based on their importance:

  • Priority 0 (Sanity): Critical basic functionality test cases.
  • Priority 1 (Core Functionality): Test cases covering essential features and integration flow.
  • Priority 2 (Recent Changes): Test cases related to recent modifications.

Manual vs. Automated Regression Testing

While manual regression testing can be labor-intensive, automation offers efficiency and repeatability. Decide based on the project’s scale, timeline, and complexity.

Types of Regression Testing

1. Corrective Regression Testing: Ensures the system functions as expected after changes without testing the existing code itself.

2. Retest All Regression Testing: Repeats tests multiple times, leading to inefficiencies.

3. Selective Regression Testing: Selects and runs relevant test cases from existing suites, optimizing test coverage.

4. Progressive Regression Testing: Introduces new test cases for newly added features.

5. Complete Regression Testing: Comprehensive testing for significant code changes or optimizations.

6. Retest-All: The main idea of this testing is to re-execute all the test cases in the testing suite to make sure that there are no bugs due to a change in the source code of an application. This type of testing demands a lot of time and effort from the QA team compared to other types.


Regression testing is a cornerstone of software development that safeguards against unintended consequences of modifications. By identifying and rectifying issues early, developers can ensure a consistent and high-quality user experience. Understanding the types and best practices of regression testing equips development teams to navigate the challenges of software evolution effectively. In this fast-paced industry, mastering regression testing is essential for delivering reliable, bug-free applications.

if you still have any questions left and want to know more about it or wish to conduct regression testing for your products, then connect with us today. We would be happy to guide you through the testing process with our expertise and make your development journey seamless.