Regression Testing vs Sanity Testing: A Thorough Understanding

28 Jun, 2023 | 5 minutes read

In the captivating world of software development and quality assurance, two essential elements come to the fore: sanity testing and regression testing. Both are crucial for ensuring the performance and reliability of software applications. 

In this article, we’ll explore the key differences between sanity and regression testing while highlighting their significance as integral parts of a successful software development process. So join us as we unravel the intricacies of these vital testing techniques – an exploration that promises to leave you with valuable insights into the world of software quality assurance.

Understanding the Software Testing Landscape

Before we dive into the specifics of sanity testing and regression testing, it’s essential to understand the broader landscape of software testing. Quality assurance (QA) teams employ a wide array of testing methods to ensure that software applications are reliable, secure, and user-friendly. These methods range from smoke tests — rapid assessments of basic functionality — to more in-depth and targeted tests.

Software testing is performed at different stages of the software development lifecycle, and each testing method has its unique purpose and importance. For instance, a test case, a set of conditions under which a tester can determine whether an application, software system, or one of its features is working as it was originally established for it to do, is fundamental to many testing processes.

Unpacking Sanity Testing

Sanity testing is a subset of regression testing. It’s a quick, high-level check performed on a software build to ensure that the added or modified functionalities are working as intended. This testing method is performed after minor changes or fixes in the code to ensure that the new functionality doesn’t disrupt existing functionalities.

The objective of sanity testing is to avoid wasting time and resources on a build or functionality that is fundamentally flawed. It’s a surface-level testing that doesn’t delve into the intricacies of the software but rather verifies that the logic of the new functionality is sane and doesn’t cause immediate crashes or failures.

Here are some reasons why sanity testing is essential:

  1. It identifies any major issues early in the development process, saving time and effort.
  2. It accelerates the testing process by focusing on new functionalities.
  3. It prevents unnecessary further testing if the build is fundamentally flawed.
  4. It reveals any major bugs or issues that need to be addressed before further testing can proceed.
  5. It ensures that new functionalities don’t disrupt or break existing functionalities.

Delving into Regression Testing

Regression testing, on the other hand, is a more extensive form of testing. It’s performed after any substantial changes in the software, such as a code change, bug fix, or update in functionality. The primary purpose of regression testing is to ensure that these changes haven’t inadvertently introduced new issues into previously working functionalities.

Regression testing is not a surface-level testing; it’s a deep dive into the software’s functionality, testing all areas impacted by the recent changes. This form of testing is typically executed on stable builds and often involves automation to ensure a thorough examination of all functionalities.

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Here’s a comparison of sanity testing and regression testing:

Sanity TestingRegression Testing
Checks stability of new functionalitiesChecks stability of all impacted areas
Part of regression testingIndependent testing
Before regression testingAfter sanity testing
Surface-level testingIn-depth testing
Limited functionalitiesAll impacted functionalities
Uses scriptsUses scripts
Often carried out manually, but can be automated as wellOften automated, but can be carried out manually as well
Complete test casesComplete test cases
Shallow and broadExtensive and in-depth
Not routine, short-timesRegresses even the smallest module

Sanity Testing vs Regression Testing: The Key Differences

While sanity testing and regression testing are closely related, there are some key differences:

  1. Focus: The focus of Sanity Testing is after a build, to make sure that the environment is stable which is achieved with testing the main functionalities through end to end testing or happy path flows. Some of those test cases are create order, create customer etc. It does not go into details like regression testing where we test every possible functionality. Sanity testing is used to make sure that the most common functionalities are stable, and everything is ready for Regression testing to be performed. In short, it’s the same structure as a regression test suite, with only the most basic functionalities.
  2. Depth: Sanity testing is considered a surface-level testing, while regression testing is not. Regression testing delves deeper into the software, testing all impacted functionalities.
  3. Automation: Both sanity testing and automation testing can be performed manually and with automation scripts.

The Importance of Both Testing Methods

Both sanity testing and regression testing play crucial roles in the software development and QA process. They help ensure that new functionalities work as intended and don’t disrupt existing functionalities, contributing to a better user experience and more reliable software products.

Making the Choice: Sanity Testing or Regression Testing?

Contrary to choosing between sanity testing and regression testing, best practices call for their sequential execution. Ideally, sanity testing serves as an initial check on functionalities. Subsequently, regression testing, unconstrained by time, provides a comprehensive examination of all features, assuring that new changes haven’t disrupted the existing functionalities. Thus, these two methods should be seen as complementary steps in a robust software testing process.

The Role of Automation in Testing

Automation plays a significant role in modern software testing, particularly in regression testing. By automating critical functionalities, the QA team can save time and resources, increase test coverage, and improve the accuracy of testing results. However, not all tests can or should be automated, and the decision to automate should be made based on the project’s needs, the complexity of the tests, and the resources available.

The Impact of Code Changes and Bug Fixes

After implementing code changes, bug fixes, or new features during a sprint, both sanity and regression testing should be performed. These testing procedures, particularly crucial at the end of each sprint in agile development before production deployment, ensure new changes have not inadvertently introduced errors or disrupted existing software functionality.


Sanity testing and regression testing are two vital cogs in the machine of software development and QA. They help ensure that software applications are reliable, secure, and user-friendly, and they play a significant role in maintaining the quality of software products.

At ⋮IWConnect, we provide comprehensive QA testing services, including both sanity and regression testing. Our experienced QA team uses a variety of testing methods and tools to ensure that your software applications meet the highest quality standards.

Remember, in the world of software development, thorough testing isn’t just an option; it’s a necessity.