What Is Regression Testing?
These Regression tests should be performed regularly whenever changes are made to the product, to make sure that the existing features still work as intended.Basically, it asks a key question: Did the latest changes break something that was working before?
Any QA team that has dealt with a continuous integration or release process will tell you that this is the test they are most worried about.
Even if new features pass all the new tests with flying colors, they might fail some of the older ones, and regression testing helps find these issues.
In this guide, you will learn all about regression testing, including why it’s important, when to use it, the different types, available tools, and best practices to follow.
Why This Testing Process Matters
As long as companies keep updating their software, regression testing will keep being important.
The business reason for doing regression testing is clear.
The global market for testing is expected to reach $48.17 billion in 2025 and is projected to grow to $93.94 billion by 2030, according to Mordor Intelligence.
This shows how much companies are willing to invest to prevent defects.In the State of Testing 2025 report, 46% of enterprises say that automated regression testing is the first type of testing they automate because it saves costs.Test automation can reduce the cost of fixing defects by an average of 57%.However, the cost of fixing errors grows rapidly at every stage of the software development cycle.
Moreover, This testing approach gives developers confidence that existing functionality continues to work correctly.
It supports continuous delivery and deployment, especially in agile and DevOps projects.
When Should These Tests Be Executed?
Testing should be done regularly, especially when there are changes to the product.
These changes can include new features, bug fixes, rework, or improvements to functions, configurations, performance, or security.Some of the most common situations that require regression testing are:
– When new features are added
– When defects have been fixed
– When the product or system is restructured or optimized
– When there are changes to configurations or environments
– When performance or security fixes are implemented
– Before major releases or updates
Companies that have well-established regression testing practices perform these tests on every check-in or pull request with a full test suite.
They also conduct tests on a nightly or weekly basis before any major release.
Different Approaches Used by QA Teams
A QA team often decides which type of testing to use based on factors like available resources, time, and the nature of the change.
Corrective regression testing – this type is used when no changes have been made to the system being tested.
It uses existing test cases.
Selective regression or partial regression testing – this method is used when testers know which parts of the system are affected.
Only the changed or impacted modules are retested.
Complete regression testing or full regression testing – as the name suggests, this involves retesting the entire system.
It is usually done when there are major changes or enhancements to the system being tested, or when there are significant technological upgrades.
Progressive regression testing – this is used when there are changes to existing requirements.
In addition to using existing test cases, new test scenarios must be created to cover the new specifications.
Unit regression testing – this is used to retest a single software component after it has been changed.
Visual regression testing – this is used to detect unexpected visual changes on a web page or application.
Regression Testing vs. Retesting: What's the Difference?
While these two terms might seem similar, they are different in several ways, as outlined below.
Regression Testing
Retesting
Purpose
To ensure that changes do not introduce defects in previously working features
To confirm that a reported defect has been fixed
Scope
Wider
Narrower
Passed test cases from previous cycles
Failed test cases from the last test cycle
Automated
More suitable for automation
Can be manual or automated
Timing
Performed after a code change
Performed after a bug fix has been implemented
In short, retesting focuses on a specific defect and checks whether it has been resolved, while regression testing looks for new issues that may have been introduced by the changes that originally caused the defect.
How QA Teams Execute These Tests
The steps below are commonly followed by QA teams during testing.
Detect the change – this involves identifying the exact code or system component that has been modified and the features that may be affected.
Assess the impact of the change – in this step, testers evaluate the modification to understand its possible effects on the system.
The goal is to find out which features are likely to be affected directly or indirectly.
Select test cases – based on this impact analysis, testers prioritize the most important test cases, focusing on those that are most likely to fail.
Decide what to automate – since tests are often run frequently, it’s important to choose test cases that provide the best value and are stable, and automate them.
Exploratory tests can be done manually on a regular basis.
Execute the tests – tests should be run in an environment that closely resembles the production environment, preferably as part of the CI/CD pipeline.
Analyze test results – in the final step, testers review the results, identify any discrepancies, and recommend corrective actions.
Top Automation Tools for Software Testing in 2026
When choosing the best testing tool, you have to consider your needs and budget. You should also evaluate other factors such as support, ease of learning and use, flexibility, extensibility, and reporting options. Some of the most popular regression testing tools include:
Selenium – one of the oldest regression testing automation tools for websites and has been adopted by over 31,000 companies as of 2025 according to
Playwright – one of the new kids in the block with a strong emphasis on performance, cross-browser compatibility, and automated waiting for dynamic content.
Cypress – a JavaScript-based tool that has taken the development community by storm.
Katalon Studio – another tool for web, API, mobile, and desktop application testing.
testRigor / Testim / mabl – these AI-driven tools help users create self-healing test suites for faster, more reliable regression testing with minimal maintenance.
Appium – one of the most popular open-source regression testing automation tools for mobile applications.
JUnit / TestNG / pytest – popular frameworks for unit regression testing.
AI-assisted code generation and self-healing test suites is one area that many testing tools are investing in heavily in 2026. The global market for testing automation is projected to grow at a CAGR of approximately 15.3% to reach $29.29 billion by 2025 according to GlobeNewswire
Best Practices for Reliable Software Releases
Based on our experience, we have compiled a list of best practices that you should consider when carrying out regression testing.
Automation is the way forward – manual regression testing can only be used for selected, infrequent tests. It is advisable to automate high-risk tests that are frequently executed.
Adopt a risk-based approach – rather than trying to cover every aspect, identify the areas that require more attention based on the impact of changes.
Treat the regression suite like production code – invest time in maintaining your regression suite by removing irrelevant test cases, addressing flaky tests, and eliminating code duplication.
Run regression tests early and frequently – rather than reserving regression testing for the end of the cycle, run a few quick tests after every code commit.
Measure and report testing metrics – such metrics offer valuable insights into the efficacy of the regression strategy.
Use production-like test data and environments – half of the failed regression tests are attributed to environment or data differences
Common QA Challenges and How to Solve Them
Some of the common challenges encountered in regression testing include:
Large regression test suite and slow test execution – address this by executing tests in parallel or split the test suite into smoke/full regression
High maintenance costs – invest in self-healing test automation tools or adopt page object model to reduce flaky tests. Note that test automation maintenance costs peak after the first year of adoption and only about 25% of enterprises see immediate ROI on test automation investments (Deloitte)
Flaky tests – address this by isolating tests that frequently pass/fail under the same conditions and fixing the underlying causes.
Test prioritization – rely on impact analysis rather than intuition to decide which tests to rerun.
