The difference between Smoke and Sanity Testing
According to ISTQB, both sanity testing and smoke testing are types of “initial testing,” which should be performed early in the testing process to ensure that the software is stable enough to proceed with further testing. ISTQB acknowledges that the terms “sanity testing” and “smoke testing” are often used interchangeably and that there is no strict definition or standard for either term.
While ISTQB may view smoke testing and sanity testing as similar types of initial testing, there are major differences between the two types of testing. They actually serve different purposes and are used at different stages of the testing process.
Smoke testing is typically performed at the beginning of the testing process. Smoke testing is usually done by executing a set of basic tests that cover the main functionalities of the software. If the software passes these tests, it is considered stable enough to proceed with more comprehensive testing. Smoke testing is quick and relatively simple to perform, which makes it a valuable tool for identifying major issues early in the testing process.
On the other hand, sanity testing is performed after major changes have been made to the software, such as after a bug fix or a significant new feature has been added. The purpose of sanity testing is to ensure that the changes have not introduced any new issues or broken any existing functionalities. Sanity testing is more focused and in-depth than smoke testing and is usually performed on a smaller subset of the software’s functionalities.
Another key difference between smoke testing and sanity testing is their scope. Smoke testing covers the main functionalities of the software, while sanity testing is usually more targeted and specific. Smoke testing is typically performed on a fresh installation of the software, while sanity testing is performed on a system that has already been set up and configured.
Fun fact*
The term “smoke testing” originates from the world of hardware testing. In the early days of electronics manufacturing, when a new item was produced, it was tested by powering it on and observing whether or not any smoke was emitted.