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.