What is Smoke testing? - A Detailed Guide

What is Smoke testing? – A Detailed Guide

What is Smoke Testing?

“What is smoke test” is a widely asked question when it comes to software testing. A smoke test is a type of software test that verifies that the most important functions of a program work. It is also known as “Build Verification Testing” or “Build Acceptance Testing”. The goal of smoke testing is to determine if a build is stable enough to proceed with further testing. Smoke tests are typically a subset of the full product test suite and involve basic functionality tests. Smoke testing is often used as the first step of a larger testing process, as it helps to identify issues quickly before more time is spent diagnosing and repairing problems. 

In this article, we are going to know “what is smoke test” and how it’s used in the IT industry. Let’s get started.

When to use Smoke Testing?

Smoke Testing is typically done at the start of a development cycle, after a build has been deployed to a test environment, to verify that the basic functions of the application are working correctly.

Let’s look at some scenarios with smoke testing examples.

1. New Feature or Functionality Release

A popular smoke test example is testing a product when releasing a new feature. Releasing new features or functionalities is a frequent behavior for most software products.  As the releases are frequent, the testing team might not get a long duration to complete a test round.

During this scenario, the testing team can maintain an automated or manual smoke test suite to verify the stability of the product in each milestone release.  Once a new feature or functionality is added to the product, a defined software smoke test suite can be executed to check whether the addition of the new feature has caused any issues. 

2. Major Bug Fix or Update

After a major bug fix or update, smoke testing can be used to verify that the product is still in a stable state. 

A smoke test on a major bug fix would involve testing the fix to ensure it successfully resolves the bug. This could include retesting the functionality of the software, running the code through an automated testing suite, and examining the code to ensure it is free of any errors. Additionally, the test should include ensuring the bug fix does not introduce new bugs or have unintended side effects.

3. System Upgrade

After a software upgrade or patch, testing should ensure that the new smoke test software is compatible with the existing product.

For a system update, a smoke test would involve running basic tests that interact with the new system and checking for any unexpected errors or crashes. This would include running common scenarios, such as logging into the system, navigating through the smoke test software, and running basic queries. If any unexpected errors or crashes occur during the smoke test, the system update should be further investigated before being deployed.

4. Major Code Refactoring

Another popular smoke test example is testing the product after major code refactoring. After a code refactoring or major change in the code base, smoke testing can be used to ensure that the code is still functioning as expected.

5. Complex Branch Merge

After merging branches or merging multiple code changes, smoke testing can be used to ensure that all the changes have been successfully merged and the product is still in a working state.

A software smoke test after a branch merge would involve running a set of tests to ensure that the merge did not introduce any new bugs or regressions into the codebase. This could include checking that the code compiles correctly, that the unit tests pass, and that the application still functions as expected.

The Purpose and Importance of Smoke Testing

The main purpose of smoke testing is to identify major issues and quickly determine the overall stability of the application. Smoke testing helps to identify major issues and defects early in the development process so that they can be easily fixed before proceeding with more comprehensive and detailed testing. Smoke testing is also an important part of regression testing, as it helps to identify newly introduced issues on existing features that may have been caused by recent changes in the application code.

Characteristics of Smoke Testing

1. Smoke tests are executed quickly

Smoke testing is designed to be quick and easy to run. It should take only a few minutes or hours to run, depending on the size of the application. The quick nature of smoke tests ensures that any major issues can be identified and resolved quickly, helping to save time and money. 

2. Smoke Tests are Non-exhaustive

Smoke tests are non-exhaustive as they are designed to quickly determine whether a product is stable enough to be tested further. It does not cover every feature of the smoke testing software. It is designed to be a high-level test of the most important functionalities. They provide a way to identify major problems so that developers and testers can focus their efforts on the most important issues.

3. Smoke tests need to be Automated

Smoke testing should be automated using smoke testing software so that it can be run quickly and easily. Automated tests can be run more frequently, as needed. Automation also ensures that the tests are consistently executed and reported in a timely manner, which allows developers to focus on more important tasks. Automated smoke tests also allow for easier regression testing, and can easily be incorporated into Continuous Integration (CI) pipelines.

4. Smoke testing is a Non-intrusive approach

The non-intrusive nature of smoke testing offers many benefits. It allows testers to quickly identify major issues without having to dive deep into the code. This makes it easier and faster to identify any major issues in the system. Additionally, non-intrusive testing helps to reduce the cost of testing by having less time spent on debugging and fixing errors. 

5. Smoke tests need to focus on Critical Paths

Software smoke testing should be focused on the critical path of the application, the most important features that need to work correctly. This can help reduce the risk of the project or process failure due to a system error.

Benefits of Smoke Testing

Smoke testing provides multiple benefits for the software development life cycle due to its nature of execution. Let’s look at some of the major benefits gained through smoke tests software.

  1. Helps to identify major issues quickly Software smoke testing can identify major issues in an application quickly and efficiently saving time and resources that would be wasted if deeper tests were performed on an application.

  2. Helps to ensure quality – Smoke tests help to ensure quality by identifying the most critical functions of a software application and verifying that they are working correctly.

  3. Helps to identify problems early in the development cycle – Smoke tests are usually performed early in the development cycle. This helps to identify problems early in the process, which means they can be fixed before they cause major issues later on.

  4. Helps to ensure compatibility – Smoke tests can be used to ensure that the application is compatible with its intended and multiple environments. This ensures that the application will work correctly when it is released.

  5. Helps to reduce cost – Because the scope of smoke testing is limited to the most basic functionality, it is efficient and cost-effective.

  6. Provides Increased Confidence – Smoke testing can give developers and testers more confidence in the quality of the application. This can help to reduce stress and increase morale.

  7. Facilitates Increased speed of deployment – Smoke testing can quickly identify functional issues that may impede the successful and quick deployment of a product.

Limitations of Smoke Testing

Let’s look at some major limitations QA Engineers and Developers face with smoke testing

  1. Smoke testing is not a substitute for other types of testing – Smoke tests are usually a small subset of tests that are run whenever a new build of an application is ready. It only tests the most important functionalities. Therefore it is not good to consider a smoke test as a substitute for other testing types such as integration, system, or acceptance testing.

  2. Smoke testing is Limited in scope and depth – The major drawback of smoke tests being limited in scope is they may fail to cover all areas of the system, Due to this some bugs may remain undetected.

  3. Smoke testing will not detect performance issues – Smoke tests do not provide any meaningful metrics or data to analyze the performance of the system such as response time or scalability, that can only be detected by running comprehensive tests.

Smoke Testing vs Sanity Testing

Smoke testing and sanity testing are both types of software testing that are used to identify major defects in a software build. Smoke testing is a broad test used to determine if the system is stable enough to be tested further, while sanity testing is a more focused test used to determine if a specific feature or functionality works as expected.

Smoke testing is a non-exhaustive, quick check of the system’s most important functions and features, and is done early in the software testing process. Sanity testing is done after smoke testing and is a shorter and more focused test of a specific feature or functionality. Sanity testing focuses on the most critical sections of the system and is used to identify major issues with a specific feature or functionality.

How does Smoke Testing work?

Smoke testing typically involves running a set of basic tests on a software application to ensure that it can perform its most important functions. These basic tests might include testing the application’s user interface, basic navigation, and data entry and retrieval. If the application passes these tests, it is considered “smoke tested” and is ready for more detailed testing.

Types of Smoke Testing

Smoke Testing can be categorized as Formal and Informal Testing

1. Formal smoke testing

In this method, the development team delivers the application to the Test Lead. Then the test lead will instruct the QA team to conduct smoke testing. Once the testing team concludes the smoke testing, they will send the smoke testing report to the test lead.

2. Informal smoke testing

Here, the Test lead informs that the application is ready for testing. The test leads do not instruct the QA team to carry out smoke testing, but still, the QA team starts testing the application by conducting a smoke testing round.

Different ways to perform Smoke Testing

1. Manual Testing

Manual smoke testing involves running a series of basic tests manually to ensure that the software behaves as expected. It typically involves testing the most basic functions of the software such as logging in, creating a new account, viewing a list of data, and performing basic searches. If any of these tests fail, the software is considered to be in an unstable state and further testing should not be conducted until the issue is fixed.

2. Automation Testing

In automation testing, you use smoke testing software to automate the test execution. Automated smoke test suites are used to verify that an application is functioning correctly before more in-depth testing is performed. Automated smoke tests can be used to identify any major issues that need to be addressed before more thorough testing is performed.

3. Hybrid Testing

This is a combination of both manual and automated testing, where manual tests are used to supplement automated tests. It combines the benefits of manual testing, such as the ability to test complex scenarios, with the benefits of automated testing, such as faster test execution and the ability to run tests repeatedly. Hybrid testing is used to improve test coverage and is especially useful for ensuring that complex user flows are tested accurately and consistently. 

How to perform Smoke Testing on Testsigma?

You can use Testsigma as a smoke tests software to simplify the smoke testing process. It allows users to create automated test scripts and execute them against their application. Testsigma also provides an in-depth analysis of the results and allows users to debug any errors. With Testsigma, organizations can carry out quick smoke test rounds to detect any issues in their applications and fix them.

Real Time Website and Web App Testing

Testsigma is a modern, cloud based test automation platform that enables users to quickly and easily create automated tests for real-time testing of websites and web applications.

Web Automation and App Testing

Testsigma can be used to test web applications on different platforms and browsers.

Real Time Mobile App Testing

Testsigma is used for real-time mobile application testing using its easy-to-use and intuitive interface. It is compatible with both Android and iOS platforms and supports a wide range of mobile application types, including native and hybrid applications.

Best Practices for Smoke Testing

  1. Analyze the software requirements thoroughly to understand the expected behavior.

  2. Develop a comprehensive test plan that outlines the tests that should be performed and the expected results. It helps to ensure that testing is conducted efficiently, as it provides a clear understanding of what tasks must be completed, by whom, and when.

  3. Design simple and straightforward test cases.

  4. Identify and prioritize the most important test cases. You should only choose test cases that cover the most critical areas of the system.

  5. Fast execution of the tests. Smoke testing should only take a few hours to complete.

  6. Document the test results as test reports. Test reports are necessary to provide relevant parties with an overview of the quality of a product or service.

  7. Conduct a triage and review the results.

  8. Repeat the process for each subsequent release of the system.


Let’s conclude what is Smoke Testing? In this article, you learned about what is smoke test. When to use Smoke Testing?, Smoke testing examples with the real world, The Importance of Smoke Testing, Characteristics, Benefits, Limitations, Types, and Best Practices of Smoke Testing. Further, we discussed the difference between sanity testing and smoke testing.

Frequently Asked Questions

Why is it called smoke testing?

The term “smoke testing” originated in the hardware industry, where it was used to refer to a type of test in which a device was powered on and checked for any visible signs of smoke or fire. The analogy was later applied to software testing, where a smoke test is used to check a software build for basic functionality and identify any major issues that need to be addressed.

Who performs smoke testing?

Smoke testing is typically performed by software testers or quality assurance personnel. Developers too can use smoke testing to verify that the code they have written is functioning as expected.

Is smoke testing manual or automation?

Smoke testing can be either manual or automated. Also, it can take the nature of a hybrid too. Hybrid typically refers to a combination of manual and automated testing techniques. 

Is smoke testing black box?

Smoke testing can be done by a person who has internal code knowledge such as a developer. In that case, the developer can be categorized as a white box tester. Also, smoke testing can be done by a person who doesn’t have internal code knowledge such as Quality Assurance Engineer. At that time tester will be considered a black box tester. Usually, smoke testing falls under black box testing but there can be situations where it can become white box too.

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