What is Regression Testing? | Methods & Benefits

What is regression testing?

One kind of QA software testing called regression testing makes sure that upgrades or modifications to an already-existing software product don’t interfere with functionality that was working before. Do things still function as expected? is the question posed by a regression test. “Regression” refers to a malfunction or bug in a different portion of the system that is brought about by a new release; hence, “regression testing.” 

Regression testing is typically performed by a development team as part of your CI/CD pipeline in an agile testing environment, but it can also be done during development as part of the test suite after the conclusion of a development sprint. Regression test difficulty and business incentives will determine how frequently you should run them.

Why is regression testing important?

Regression testing is a crucial safeguard against serious risk since it reveals whether your current functionality is still operating as intended, which is likely to be very important for your company. 

Unseasoned developers may be taken aback by the likelihood of that risk materializing. Modest alterations to the code can have disproportionate and unforeseen effects on disparate components of the product. As a result, the risk frequency is greater than you may anticipate.

Additionally, releasing faulty new features is a far less serious consequence for the company than breaking something that customers already depend on. When companies go from startup to scaleup, preventing regression has a greater impact than rapidly adding new features. Breaking an established feature is extremely disruptive and will be very difficult for your CS team to handle. Regression testing thus becomes increasingly crucial as your user base grows.

Since regression testing is among the most popular test kinds that your company performs, it’s crucial to consider regression testing from an operational standpoint. If done incorrectly, it might slow down your CI/CD cycle and add up to considerable costs for your company.

How is regression testing different from… re-testing, unit testing, functional testing 


Retesting is the process of looking for a particular flaw that you have recently discovered (and maybe solved). Regression testing is the process of looking for flaws in the product as a whole after a new feature release.

Regression testing is an outcome rather than a technique, therefore a suite of tests of various kinds can be included. This is in line with unit and functional testing. That could include any other type of test, but it’s nearly a given that it will include functional tests, unit tests, and regression tests (most of which involve functional test case execution).

How to prioritize your test cases for a regression test 

Retest all is a regression testing methodology that entails, exactly as it sounds, a thorough re-execution of every test case on your system. This takes a lot of money and time. Rather, companies are more likely to pick a few test cases and run with them.

How many test cases?

The question of “how much” and “how often” regression testing should be done cannot be answered, even though, as a testing business, we usually advocate for a rigorous and proactive testing methodology.

Rather, we would advise determining the cost and impact level of two or three different regression suite tiers. To ensure you can rapidly consult your data throughout the decision-making stage, make sure you can assess the time and financial cost of executing each tier of the test suite. This will help your company determine the right depth to go to at that particular time and motivate you to monitor the overall amount of testing you are doing to see whether it fits within your budget and risk tolerance. 

What kind of test cases?

The issue of which test cases to prioritize in a particular regression suite will arise once you have decided against “retesting all.” 

Once more, this is frequently unique to your own company and goods. However, we have observed that our clients rank the test cases in their regression suites according to the following values. 

  1. High-vulnerability test cases are used to identify regions of your product that are more likely to have errors and problems. 
  2. Crucial test cases, to eliminate the most significant errors from a legal, safety, or commercial standpoint
  3. Test cases involving complex integrations that are both business-critical and prone to failure 
  4. How pertinent those examples are to a certain login or release, for example, login test cases for changes to the login system 
  5. and a range of test scenarios. A set of test cases that collectively cover the majority of system modules is chosen to guarantee that every component of the product is evaluated.
  6. cases are chosen at random.  You can make sure that you are running a complete system test across several regression suites by iterating through the test cases. 
  7. a mix of the aforementioned.  Regression test cases typically represent a variety of distinct priorities. Regression suites include making decisions based on a trade-off between time, risk, and competing priorities. 

Considering automation for regression testing

Regression testing can be carried out automatically or by hand using testing tools. 

Manual regression testing entails retesting the program after modifications have been made. It could take a lot of time and a big team of testers to complete this. On the other hand, software tools are used in automated regression testing to automatically retest the software. Setting up and maintaining the testing instruments needs specific knowledge and abilities, although it can be quicker and more effective than manual testing.

Regression testing is a popular test category and is one of the easiest tests to automate, which appeals to developers.


In conclusion, regression testing plays a crucial role in ensuring the stability and reliability of software systems, particularly in the context of frequent updates and changes. By systematically retesting modified components, regression testing helps detect and prevent the introduction of new defects into the software. This process can be efficiently executed through automation testing with tools like Selenium. Leveraging Selenium automation testing not only streamlines the regression testing process but also enhances its accuracy and repeatability. The benefits of regression testing, coupled with the efficiency of automation testing with Selenium, contribute to overall improved software quality, faster release cycles, and increased customer satisfaction

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