Smoke Testing vs. Sanity Testing: A Guide

Ensuring the quality of the product is the main goal in software testing environments. However, delivering top-notch releases demands efficient testing strategies. 

Two fundamental yet often confusing testing types, smoke testing and sanity testing, serve unique roles in validating software builds. 

Understanding the difference between smoke testing vs sanity testing enables you and your QA team to optimize efforts. And not only that, from what we’ve observed, your bug escapes will be reduced significantly.

That said, this guide unpacks these testing types in detail to help testers know when to use each effectively. 

Key Takeaways

• Smoke testing is the first stability checkpoint in the QA cycle. Automated smoke suites integrated into CI/CD can reduce release cycle time by about 50% and catch up to 80% of critical bugs early before deeper testing begins.
• Sanity testing provides fast validation of recent fixes and new features. Structured sanity testing lowers escaped defects into production by about 18% and keeps release timelines moving without full regression cycles.
• Scope is the biggest differentiator. Smoke tests validate the broad core workflows of a system to decide if deeper testing should proceed, while sanity tests focus only on updated modules to confirm functionality without regressions.
• Both test types face challenges without strong test management. Issues like bloated and flaky suites, duplication between smoke sanity and regression, and a lack of documentation reduce testing efficiency and reliability.
• Teams that apply smoke and sanity testing consistently before regression testing ship faster with fewer defects. Early validation prevents wasted QA effort, improves confidence across engineering and product, and increases overall release velocity by nearly 30%.

What is Smoke Testing?

Smoke testing is a preliminary level of software testing. It focuses on verifying whether the key functionalities of a software build are working correctly. It’s also checked if the build is stable enough to proceed to further testing stages. 

Also known as build verification testing or confidence testing, it serves as a quick check to detect major issues early in the development lifecycle.

Additionally, some of the key aspects of smoke testing include:

• Purpose: Determine if the software build is stable enough for further detailed testing.
• Scope: Covers only the most important and fundamental features of the application. There isn’t any sort of exhaustive testing. 
• Execution: Can be performed manually or automated using predefined test scripts.
• Timing: Conducted immediately after a new build is delivered by the development team.
• Outcome: If the smoke test passes, the build moves on to deeper testing. Such as unit, integration or regression tests. However, if it fails, the build is sent back to developers for fixes before any further tests are conducted.
• Focus areas: Ensures core functionality works as expected. For example, application startup, main workflows, critical user actions, etc. 
• Test set: Consists of a minimal set of test cases. Ones that are designed to cover high-level features quickly.

So, basically, you can think of smoke testing as an early warning system to detect show-stopping defects. It helps ensure that resources are not wasted on unstable builds. 

What is Sanity Testing?

Sanity testing is a focused verification process that’s performed after a software build has passed smoke testing. 

Its primary objective is to confirm that specific bug fixes, enhancements or new features function correctly. Without them introducing new defects. It is ensured that the changes made are stable enough for more detailed testing.

The main things about sanity testing that you need to know are as follows.

• Purpose: Verify that recent changes in the codebase work as expected. And have not negatively impacted the application’s core functionality.
• Scope: Narrow and targeted. Focused only on the modules or components that are affected by recent changes rather than the entire system. 
• Execution: Usually manual or selectively automated. Sanity tests are often unscripted to allow flexibility in verifying fixes efficiently. 
• Timing: Conducted after a build passes smoke testing. Typically, it is carried out before full regression testing. 
• Quick assessment: Designed to provide rapid feedback. It is often completed within a short timeframe to minimize testing cycle delays. 
• Role: Acts as a quality gate, ensuring that only stable and reliable builds proceed to comprehensive testing phases. 
• Impact: A Study by Lech Madeyski on test failures induced by software defects shows that teams incorporating dedicated sanity testing reduce the rate of defects escaping into production by approximately 18%.

All in all, sanity testing ensures focused validation on new or changed functionalities. It complements smoke testing and is critical in agile and continuous integration environments.

How Does Smoke Testing Work?

Smoke testing involves a systematic workflow designed to quickly verify the stability and critical functionality of a new software build. Here’s how it works:

• Identification of critical test case: The process begins by selecting a predefined set of test cases. Ones that cover the most important features and workflows of the application. These are high-priority scenarios like user login, navigation, data input/output and key business functions. 
• Preparing test environment: Before execution, the testing environment needs to be configured to accurately mirror production or staging conditions. This ensures that the test results reliably reflect real-world behaviour. 
• Deploying the new build: Once the environment is ready, the latest software build is deployed to the test environment. 
• Executing smoke tests: The predefined test cases are executed against the deployed build. This can be done manually or, how it’s done more commonly, through automated test scripts integrated into CI/CD pipelines.
• Analyzing results: The outcomes of the smoke tests are then evaluated to determine if the build is stable. If the core functionalities pass, the build is approved for more comprehensive testing.
• Handling failures: If any critical test cases fail, the build is rejected and sent back to developers for immediate fixes. This prevents further testing on unstable builds and saves time and resources.
• Feedback and reporting: Test results are documented and shared promptly with every team involved. Doing so facilitates quick turnaround and transparency. 

Note that integrating smoke testing into CI/CD pipelines is key to accelerating this process. Automated smoke tests can run immediately after each build deployment, with organizations reporting 50% cycle time reductions due to smoke test automation, as per Virtuoso QA. The feedback is provided rapidly to the development teams, and faster iterations are enabled.

How Does Sanity Testing Work?

Sanity testing is initiated after a software build passes the smoke testing phase. It verifies specific changes, such as bug fixes or new feature improvements. 

The goal is to validate that all the updates work correctly and do not negatively affect other parts of the application. Sanity test cycles are short, typically 30-60 minutes, and are flexible to adapt to dynamic requirements.

That said, the typical workflow of sanity testing includes:

• Selection of test focus: First, QA teams identify recent changes or bug fixes to determine the specific areas or functionalities that need attention.
• Test design and preparation: Concise test cases or checklists that target the affected components are developed. Depending on the project, these tests can be manual or selectively automated to improve efficiency. 
• Execution of tests: Focused validations on selected areas are performed by the teams. They confirm that the recent changes behave a expected. The testing is generally exploratory and adaptable to dynamic requirements.
• Analysis reporting: Test results are reviewed. If there are any issues caused by recent changes, they are highlighted. The findings are documented and clearly communicated to the development team, which immediately starts the remediation process. 
• Integration with development workflows: In agile and CI/CD environments, sanity tests are sometimes automated and triggered regularly. This is done to validate builds continuously. 

You can say that this focused and rapid testing phase acts as a quality gate for new changes. 

Ready to make sanity testing faster and predictable? Book a demo of Kualitee and see how quick QA looks in action.

Examples of Smoke Testing and Sanity Testing

To really understand Smoke Testing vs Sanity Testing, here is an example.

Smoke Testing Example: Online Shopping Platform

Imagine a popular e-commerce website that frequently pushes out new builds with updates and features. After each build is deployed, the QA team performs smoke testing to check the crucial workflows. They see if the features essential for user operation are functioning or not. 

For instance:

• The tester opens the website and confirms the homepage loads without errors. 
• They check that the user registration and login processes complete successfully. 
• The process of browsing the product catalog and using the search feature is quickly verified.
• Items are added to the shopping cart. The whole checkout flow is tested, and it is ensured that there are no blocking issues. 
• Payment authorization integration is checked minimally to confirm it responds correctly. 

Once all these core features are tested and if all of them pass, the build is deemed stable enough to proceed to more advanced testing phases. However, as we mentioned earlier, if any test fails, the build is rejected immediately. The developers then fix major issues before QA invests further efforts. 

Sanity Testing Example: Payment Bug Fix in FinTech Application

Consider a FinTech mobile app where users experienced an intermittent payment failure bug. After the development fixes the issues, the QA team begins sanity testing on the new build. 

Now, how do they do that? Here’s how:

• Testers focus solely on the payment module rather than the entire app.
• They validate that payments are successfully processed without any failure using various methods. 
• Related features such as transaction history and receipt generation are also checked briefly. It is ensured that there are no regressions.
• Other unrelated functionalities, like user profile management or notifications, are skipped to save time. 

This sort of sanity test cycle provides quick validation that the fix works. And that no new issues were introduced in the payment workflows. Once the sanity test passes, the build then moves to full regression testing so that overall system integrity can be verified. 

Tools for Smoke Testing and Sanity Testing

Commonly used smoke testing tools include:

• Selenium
• Cypress
• Katalon Studio
• Jenkins

These tools automate critical end-to-end tests and integrate easily with CI/CD pipelines. They provide rapid feedback on build stability.

For sanity testing, you have the following choices. 

• Postman for API validation
• Selenium for targeted scripts

Besides this, manual testing still plays an important role for quick and focused sanity checks. 

Kualitee: The Better Choice

Kualitee stands out among the other tools, thanks to its comprehensive test management capabilities. It’s a platform that unifies smoke and sanity testing workflows in one place.

Unlike standalone tools, Kualitee offers:

• End-to-end test case management with clear traceability from requirements to execution.
• Built-in defect tracking that connects directly with test runs and release cycles.
• Real-time reporting to surface blockers early and support data-driven decisions.
• AI-powered test generation to speed coverage without increasing workload.
• Easy integration with Selenium, Jenkins and other automation tools to reduce context switching and improve team alignment.

Built for Smooth QA management. Try Kualitee now for free to simplify and accelerate your testing process.

Advantages of Smoke Testing

Smoke testing acts as the first line of defense in software quality assurance. It helps catch critical issues early to maintain project momentum. The following are some of its key advantages.

1. Early Detection of Critical Failures

Catching major defects early in the development process prevents costly downstream effects. Functionize reports that efficient smoke test suites catch about 80% of critical bugs. 

This allows teams to address showstoppers before they escalate. The early feedback loop is essential for fast troubleshooting and reduces the risk of blocking major releases.

2. Prevents Waste of Testing Resources

Smoke testing ensures that only stable builds proceed to deeper testing phases. What this does is preserve valuable QA time and effort. 

Coursera highlights that smoke testing minimizes wasted effort by filtering out fundamentally flawed builds. Due to this, development time and costs on extensive testing that would be futile on unstable software are saved. 

3. Maximizes Coverage of Important Workflows

With other types of testing, you focus on validating the overall software product. This isn’t the case with smoke testing. It focuses only on the core functionalities, and the tests achieve broad coverage of crucial application paths. All without the overhead of full regression testing. 

Tely.ai mentions that systems with less than 70% important workflow test coverage suffer up to 1.5 times more bugs in production. This can be avoided easily with smoke testing, further reinforcing its role in risk mitigation. 

4. Accelerates Continuous Delivery

Organizations that practice regular smoke testing experience up to a 30% boost in release speed. While maintaining high software quality, as per the same source from earlier. 

This acceleration supports agile methodologies. It also helps development and QA teams deliver reliable features faster in competitive markets. 

Advantages of Sanity Testing

Sanity testing offers focused and rapid validation, making it an essential practice in modern software development. Its advantages contribute to efficient, high-quality releases. 

Speaking of advantages, the following are a few notable ones that you get from sanity testing.

1. Rapid Validation of Specific Functionalities

Sanity testing provides fast feedback by quickly verifying critical parts of the application impacted by recent changes. 

According to BrowserStack, this quick feedback on software builds enables developers to address critical issues promptly. Release cycles are accelerated, and costly delays are prevented as a result.

2. Reduces Unnecessary Testing Overhead

By concentrating only on affected areas rather than the whole application, sanity testing greatly reduces the time and resources needed. This is evident most when compared to full regression testing. 

GeeksforGeeks notes that this focused approach requires less documentation and preparation. The testing process is simplified without compromising quality. This efficiency helps teams maintain speed without lowering standards. 

3. Fast Turnaround for Urgent Patches or Features

The streamlined nature of sanity testing enables you to make swift decisions. Especially regarding the build readiness for further testing or release. 

QATouch confirms that sanity testing adapts well to continuous integration workflows. It facilitates rapid iteration and deployment. As someone from the QA industry, you’ll know that this agility is vital for meeting tight deadlines in competitive markets. 

4. Reduces Production Defects Through Improved Verification

Teams that implement structured sanity testing have reported to us that they see a significant reduction in escaped defects reaching production. This is thanks to the more thorough validation of critical changes. 

Furthermore, the improved verification protocols contribute to higher software quality and customer satisfaction.

Challenges in Smoke Testing and Sanity Testing

It is obvious that while smoke and sanity testing provide various advantages, they also have their fair share of challenges. These challenges can impact their effectiveness.

1. Maintenance & Relevance of Test Cases

Smoke testing often struggles with test case maintenance. As applications get new updates, test suites can become bloated and outdated. This leads to unreliable results.

One user reported that “tests are becoming hard to manage,” and another mentioned “bloated, flaky suites where smoke/sanity/regression overlap and feel ‘meaningless.’” 

Hence, without regular reviews and updates, smoke tests risk missing critical issues or producing false positives. Resulting in time wastage and trust erosion in the testing process. 

2. Inconsistent Execution & Coverage Gaps in Sanity Testing

Sanity testing is typically manual and unscripted, causing inconsistency in execution and incomplete coverage. 

This leads to critical fixes or features sometimes not being fully validated. Users express frustration about the lack of “practical examples” and “use cases” that clarify sanity testing implementation, contributing to uneven results and coverage gaps.

3. Resource & Time Constraints

Both smoke and sanity testing require quick execution to keep up with fast development cycles. Especially in CI/CD pipelines. 

Users highlighted issues such as “execution time, flakiness, and duplication of test cases.” The pressure to deliver rapid feedback can compromise thoroughness, with teams struggling to balance speed against test quality and reliability.

4. Duplication & Overlap with Other Test Types

Another common challenge is the overlap between smoke, sanity and regression testing. 

Test cases often duplicate across suites, creating confusion about the scope and purpose of each test type. 

One user said that the suites “overlap and feel meaningless.” Pointing to inefficiencies and wasted effort that arise without clearly defined boundaries and test management.

Smoke Testing vs Sanity Testing: Key Differences

The following is a table of key differences between smoke testing and sanity testing.

Aspect	Smoke Testing	Sanity Testing
Purpose	Verify overall build stability	Confirm functionality of changes
Scope	Broad, critical end-to-end functions	Narrow, focused on recent fixes
Timing	Right after build deployment	After smoke test approval
Automation	Typically automated	Often manual or selectively automated
Documentation	Well-documented and scripted	Usually unscripted or lightly documented
Performed By	Developers and testers	Primarily testers

Best Practices for Effective Smoke and Sanity Testing

Effective smoke and sanity testing are very important for maintaining software quality without sacrificing speed. Below are some of the best practices that are recommended by experts. 

1. Prioritize Critical User Journeys in Smoke Testing

Focus smoke tests on the most vital user workflows to maximize impact while keeping execution lightweight. If a workflow isn’t highly important, skip it when smoke testing. 

TestingXperts recommends limiting smoke test execution to under 10-15 minutes to ensure quick feedback loops that don’t delay development.

Remember that automation is key. The automated smoke tests integrated into CI/CD pipelines improve consistency and speed. They enable early detection of breaking changes. More on this below.

2. Automate Smoke Tests with Clear Pass/Fail Criteria

Automation reduces human error and facilitates frequent smoke test runs. These tests are triggered by code commits or build deployments. 

That said, Enov8 says that creating clear, unambiguous pass/fail criteria for automated smoke tests is important because it helps avoid false positives that can erode trust in test results. 

Frequent, reliable execution within CI/CD pipelines enhances testing throughput and release velocity.

3. Focus Sanity Testing on Recent Code Changes

Sanity tests should be scoped tightly to validate bug fixes or new features without re-examining the entire system. TestDevLab suggests you use modular, reusable checklists to improve test efficiency and maintainability.

Try to keep sanity test cycles short. Usually minutes rather than hours. This ensures fast turnout, which can be great in agile contexts. 

4. Rotate Testers for Fresh Perspectives

Introducing different testers to sanity test cycles is an important best practice that can significantly enhance testing outcomes. 

Sanity testing, by its nature, is focused and rapid, often verifying recent changes or bug fixes in a short timeframe. However, repeated execution by the same testers can lead to complacency or tunnel vision, where some defects might be overlooked due to familiarity or biased expectations.

Rotating testers brings varied expertise and viewpoints to the process. This helps uncover hidden issues that might otherwise be missed.

5. Maintain Consistent Documentation and Centralized Repositories

Centralizing test cases, results and histories in accessible repositories supports traceability and continuous improvement. 

Consistent documentation is always needed, as it aids debugging and stakeholder communication. This ultimately speeds up problem resolution and increases reliability.

Smoke, Sanity and Regression Testing: When and Why to Use Each

A layered QA strategy helps teams optimize testing efficiency by applying each test type at the most appropriate stage of development. It balances speed and depth of coverage for better software quality. Here’s when you can use each testing type and why. 

• Smoke Testing: The Initial Gatekeeper (Perform First)

Smoke testing serves as the first checkpoint after a new build or deployment. It verifies the application’s critical workflows and the overall build stability to determine if the software is ready for more detailed testing. 

This process prevents unstable builds from progressing and saves significant QA and development resources. 

Smoke testing is fast and broad. It’s designed to unveil major issues early and is often automated for rapid feedback in CI/CD pipelines. 

• Sanity Testing: Focused Validation of Changes (Perform Second)

Following successful smoke tests, sanity testing hones in on recently introduced fixes or features. 

It provides quick verification that these targeted updates work as intended. And have not caused regressions in the affected components. 

Unlike smoke testing’s broader scope, sanity testing is narrowly focused and often manual or semi-automated, allowing for fast turnaround.

• Regression Testing: Comprehensive System Validation (Perform Last)

Once smoke and sanity testing confirm build stability and change correctness, comes regression testing. It performs a thorough check of the entire application to ensure that new updates haven’t broken existing functionalities. 

Re-executing a wide array of pre-existing tests, often automated due to their scale and complexity, is involved here. 

Although more resource and time-intensive, regression testing is needed for release confidence. You get comprehensive coverage before production deployment.

Hence, by strategically applying smoke, sanity and regression tests in this layered manner, organizations achieve efficient risk mitigation. They are able to maintain high release velocity and uphold quality standards without overwhelming testing resources.

Smoke Testing vs Sanity Testing: Closing Thoughts

Smoke testing and sanity testing are not just routine checks. They are strategic quality filters that determine whether a build deserves deeper inspection or immediate fixes.

Smoke testing acts as the stability gate. It asks one core question: Is the build strong enough for full testing? 

Sanity testing comes next with a sharper lens, confirming that recent fixes or new features behave correctly without breaking anything else. 

When both are applied consistently, QA teams avoid wasted effort and catch issues before users ever see them. Teams that combine smoke, sanity and regression testing operate with speed and confidence instead of guesswork. 

The takeaway is simple. Builds that survive vigorous early validation ship faster. They break less and inspire more confidence across engineering, product and leadership.

Want a clearer picture of costs before choosing a QA platform? Check out Kualitee’s pricing and compare plans side by side.

Frequently Asked Questions (FAQs)

Q1) What is the difference between smoke and sanity testing?

Smoke testing verifies the overall stability of a new build by checking critical functions to determine if further testing can proceed. Sanity testing focuses narrowly on checking specific bug fixes or new features to ensure they work correctly without breaking existing functionality. Smoke tests cover broad workflows, while sanity tests validate targeted changes.

Q2) What is smoke testing with an example?

Smoke testing is an initial check to confirm that key features of an application are working after a new build. For example, in an e-commerce website, smoke testing would verify that the user login, product search, adding items to the cart and checkout process function correctly after deployment.

Q3) What is an example of a sanity test?

A sanity test might involve retesting a recently fixed payment processing bug to ensure the issue is resolved and the function behaves as expected. Without running full regression tests on unrelated parts of the system.

Q4) When should smoke tests be performed?

Smoke tests are performed immediately after a new build or release deployment. This is because it has to be verified is a build is stable enough for further detailed testing. They act as a gatekeeper to avoid wasting QA resources on broken or unstable builds.