The Smoke, Sanity, and Regression Testing Triad

Key Takeaways:

• Smoke, sanity, and regression testing can be used to help your teams get the most test coverage (and the most results) out of your testing suite.

• Smoke testing verifies build stability, sanity testing confirms recent changes function as expected, and regression testing ensures existing features remain intact after updates.

• Using all three together ensures your QA process is both efficient and thorough, minimizing risk without inflating testing time.

• Smart Tests from CloudBees help teams prioritize which smoke, sanity, or regression tests to run, boosting speed and reducing manual rework.

Software testing comes in many forms, but not every type is created equal, or necessary for every scenario. Smoke, sanity, and regression testing are powerful tools for maximizing coverage and results, but knowing when and why to use each is key to avoiding bloated test cycles. We’ll break down these three testing types and how they fit into a streamlined QA workflow.

Smoke testing is a process that determines whether or not a software build is stable. QA teams use smoke testing to check if they need to continue testing on a build. Essentially, teams use smoke testing to ensure that all the major features are working as intended and whether or not the build is ready for further testing. Think of smoke tests as Stormtroopers - with their shiny white armor and hilariously bad spatial awareness - great in numbers, but they don’t usually get too far alone.

Like sanity testing, the Jedi acts as a voice of reason in the galaxy. They help mediate between factions and planets and are armed when it matters. A subset of regression testing, sanity testing is done to ensure that code changes are working as intended. These tests are run on code that is already stable, making sure that it works within the context of the rest of the build. It’s a “sanity check” to ensure the software is ready for more in-depth tests.

Lastly, we have regression tests that are like the Rebels, a rag-tag group of do-gooders trying their best to cover the entirety of a system to reach a peaceful end. Regression testing is the practice of testing an entire application after a change has been made. And yes, this means the application as a whole, from end to end. These tests are performed to ensure that all aspects of an application work when a new update is released. All elements of a code base are tested here so that no parts of the software are affected by the new additions.

Smoke testing is a fast, high-level check to confirm whether a software build is stable enough for further testing. These are the most basic tests that are run on parts of software, making sure that major components are working as intended, like login forms, loading assets, or even just clicking buttons. Smoke tests are some of the first tests run to see how the software performs.

Smoke testing is generally performed after a build has been released to a QA team, allowing them to test it for any significant issues before proceeding. If tests continue to fail, then devs know not to continue with more in-depth tests.

• They verify “stability” to continue with testing.

• Performed on critical functionalities of the application.

• A subset of regression tests, if smoke testing fails, it’s an instant rejection.

As the first checkpoint in the QA process, smoke testing prevents wasted time and effort by ensuring only stable builds move forward to more detailed testing stages.

Sanity Testing: Verify Rationality

Unlike smoke testing, sanity testing is performed on stable builds with recent changes in the code or new functionality is added. Sanity tests exist to make sure that these new functions work as intended and that the build is ready for further testing.

Sanity testing comes before or after complete regression testing, mainly to check if further regression testing is required. Smoke testing is the first step in making a build stable, while sanity tests ensure a build is verified, usually done at the end of the testing cycle

• They verify the “rationality” of the app for further testing.

• Performed on more detailed functions of the app.

• A subset of regression tests.

Sanity testing quickly confirms that recent updates behave as expected. It helps keep the development cycle efficient and focused, bridging the gap between initial checks and full regression testing.

Regression Testing: Verify Every Existing Feature

Regression testing ensures that every aspect of a software build works as intended. These are end-to-end tests that check every bit of functionality to ensure that any new changes made to the codebase haven’t affected other parts of the application.

This is generally done at the last step of the testing lifecycle after smoke testing has been completed. It’s the final step before software is passed to users to be used or tested further by the user base.

• They verify every existing detailed functionality and feature of the application.

• Regression testing should be well documented.

Regression testing is the final gate before release, ensuring new changes haven’t disrupted existing functionality. It safeguards product integrity across the entire application.

Combining Smoke, Sanity, and Regression Testing in Your SDLC for Faster, Safer Releases

In an optimized QA workflow, smoke tests are the first line of defense, run early in the SDLC to catch major issues while development is still in progress. These tests check for any significant bugs that can be found while development is still ongoing. Once these high-level checks pass, sanity testing validates that recent code changes haven’t disrupted key functionality. From there, regression testing ensures that both new updates and existing features work together seamlessly across the full application.

When used in tandem, these testing layers create a more stable, secure release process. Smoke testing verifies functionality in isolation, but without sanity and regression testing, teams risk missing deeper integration issues that surface only when components interact.

On the other hand, relying solely on sanity or regression testing can lead to bloated, time-consuming cycles, where teams spend too much time validating new features and re-checking existing ones without the efficiency that early smoke testing provides.

Smoke testing is a fast, high-level check to confirm whether a software build is stable enough for further testing. These are the most basic tests that are run on parts of software, making sure that major components are working as intended, like login forms, loading assets, or even just clicking buttons. Smoke tests are some of the first tests run to see how the software performs.

Smoke testing is generally performed after a build has been released to a QA team, allowing them to test it for any significant issues before proceeding. If tests continue to fail, then devs know not to continue with more in-depth tests.

• They verify “stability” to continue with testing. 

• Performed on critical functionalities of the application.

• A subset of regression tests, if smoke testing fails, it’s an instant rejection.

As the first checkpoint in the QA process, smoke testing prevents wasted time and effort by ensuring only stable builds move forward to more detailed testing stages.

Unlike smoke testing, sanity testing is performed on stable builds with recent changes in the code or new functionality is added. Sanity tests exist to make sure that these new functions work as intended and that the build is ready for further testing.

Sanity testing comes before or after complete regression testing, mainly to check if further regression testing is required. Smoke testing is the first step in making a build stable, while sanity tests ensure a build is verified, usually done at the end of the testing cycle

• They verify the “rationality” of the app for further testing.

• Performed on more detailed functions of the app.

• A subset of regression tests.

Sanity testing quickly confirms that recent updates behave as expected. It helps keep the development cycle efficient and focused, bridging the gap between initial checks and full regression testing.

Regression testing ensures that every aspect of a software build works as intended. These are end-to-end tests that check every bit of functionality to ensure that any new changes made to the codebase haven’t affected other parts of the application.

This is generally done at the last step of the testing lifecycle after smoke testing has been completed. It’s the final step before software is passed to users to be used or tested further by the user base.

• They verify every existing detailed functionality and feature of the application.

• Regression testing should be well documented.

Regression testing is the final gate before release, ensuring new changes haven’t disrupted existing functionality. It safeguards product integrity across the entire application.

In an optimized QA workflow, smoke tests are the first line of defense, run early in the SDLC to catch major issues while development is still in progress. These tests check for any significant bugs that can be found while development is still ongoing. Once these high-level checks pass, sanity testing validates that recent code changes haven’t disrupted key functionality. From there, regression testing ensures that both new updates and existing features work together seamlessly across the full application.

When used in tandem, these testing layers create a more stable, secure release process. Smoke testing verifies functionality in isolation, but without sanity and regression testing, teams risk missing deeper integration issues that surface only when components interact.

On the other hand, relying solely on sanity or regression testing can lead to bloated, time-consuming cycles, where teams spend too much time validating new features and re-checking existing ones without the efficiency that early smoke testing provides.

Bringing all three methods together delivers a faster, more resilient QA process, and ultimately, higher confidence in every release.

Naturally, before any soldier valiantly charges into battle, they need a plan and to prepare. The same goes for your engineering org, too. Setting up a test plan can help your devs and QA teams break up larger test suites and reinforce a resilient DevOps culture across your teams.

Steps for planning and preparing your test steps:

• Identify the scope of the testing: Scopes should include details on areas that need to be tested, objectives that need to be met, and specify the criteria for success.

• Define the testing environment: This includes specifics on what hardware and software will be used and system requirements.

• Create test cases: Your test case outlines should include details on expected results, input values, and output values. 

• Set up the testing environment: Install any necessary hardware and software and configure your system to meet your specific requirements.

• Create a test plan: Outline the steps to be taken, document the test objectives, and establish your criteria for success.

• Gather the necessary resources: This includes personnel, tools, and other resources.

With your test plan in place, the next step is monitoring performance. Test management software, combined with techniques like feature testing, can provide valuable visibility into your test suites, helping your teams gather the insights they need to optimize and continuously improve the testing lifecycle.

Steps for managing and tracking your test results:

• Execute the tests: Once the test cases are created, the next step is to execute the tests. This involves running the tests and collecting the results.

• Analyze results: After the tests are executed, the results should be analyzed. This includes looking for any unexpected results or errors that occurred during the tests.

• Track and document results: When we talk about best practices for tracking and documenting test results, we look to the top-tier test suite insights tools to make this automated and easy to analyze. 

• And with tests running smoothly, your team will need to watch and update tests as the process goes along. Teams should use the data they get from these tests to update and improve the existing tests and eventually add automation to speed up the process.

Once your test results are tracked and reviewed, the next step is to refine and maintain your test suite to ensure it stays aligned with evolving code and system changes.

Steps for maintaining and updating your tests:

• Identify test cases that need to be updated: Before updating any existing smoke, sanity, or regression test cases, it is important to identify which tests need to be updated. This can be done by reviewing the existing test cases, looking at the changes that have been made to the system and determining which tests may no longer be valid. Smart Tests helps identify the critical tests to run and visibility into your test suite health to make this step simple. 

• Analyze the system changes: Once the test cases that need to be updated have been identified, it is important to analyze the changes that have been made to the system. This will help to determine which tests need to be modified, added or removed.

• Update the test cases: After analyzing the system changes, the test cases should be updated to reflect the changes. This may involve modifying existing test cases, creating new test cases or removing outdated test cases.

• Execute the updated tests: Once the test cases have been updated, they should be executed to ensure that they are valid. If any tests fail, they should be corrected and re-executed.

• Document the changes: After the tests have been updated and executed, it is important to document the changes that have been made. This will help ensure that any future changes to the system are tested properly.

Each type of testing plays a critical role in the overall software lifecycle. While testing is often time-consuming and resource-heavy, CloudBees Smart Tests helps streamline the process and reduce the burden.

Smart Tests uses machine learning to dynamically determine which tests to run based on the specifics of each code change. Whether you’re performing smoke, sanity, or regression testing, Smart Tests help focus your efforts on the most relevant and high-impact areas, saving time without sacrificing quality.

Smoke Testing: Prioritize What Matters Most with Smart Tests

Smart Tests uses machine learning to identify which smoke tests have the highest risk of failure, helping teams focus on the most critical areas first. By surfacing high-impact tests early, development teams can detect major issues faster and streamline the path to deeper QA.

Sanity Testing: Smart Tests Eliminate Redundant Test Cycles

When validating recent code changes, Smart Tests highlights tests most likely to pass, allowing teams to avoid retesting functionality that’s already stable. This AI-driven insight helps teams zero in on potential problem areas and reduce wasted effort.

Regression Testing: Target Tests Affected by Change Efficiently with Smart Tests

Smart Tests evaluates historical performance data alongside code changes to determine which regression tests are truly relevant. This ensures teams only run what’s needed, reducing test suite bloat and accelerating release cycles without sacrificing quality.

CloudBees customers are already seeing real impact. One DevOps team doubled its release velocity by integrating Smart Tests into their QA workflows, enabling faster feedback and more efficient test execution.

With Smart Tests, your team can achieve similar results: reducing manual effort, improving productivity, and accelerating time to value. Whether you're awaiting smoke, sanity, or regression test results, Smart Tests delivers personalized updates as soon as tests are complete so you can instantly review outcomes, pass or fail.

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