1. Smoke testing originated in the hardware testing practice of turning on a new piece of hardware for the first time and considering it a success if it does not catch fire and smoke. In software industry, smoke testing is a shallow and wide approach whereby all areas of the application without getting into too deep, is tested.
A sanity test is a narrow regression test that focuses on one or a few areas of functionality. Sanity testing is usually narrow and deep.
2. Smoke testing is done by developers before the build is released or by testers before accepting a build for further testing.
The sanity test is done mostly by Testers.
3. A smoke test determines whether it is possible to continue testing.
Sanity test determines whether it is reasonable to proceed with further testing.
4. A software smoke test determines whether the program launches and whether its interfaces are accessible and responsive (for example, the responsiveness of a web page or an input button). If the smoke test fails, it is impossible to conduct a sanity test.
In contrast, the ideal sanity test exercises the smallest subset of application functions needed to determine whether the application logic is generally functional and correct (for example, an interest rate calculation for a financial application). If the sanity test fails, it is not reasonable to attempt more rigorous testing.
5. A smoke test is scripted--either using a written set of tests or an automated test
A sanity test is usually unscripted.
6. A Smoke test is designed to touch every part of the application in a cursory way. It's is shallow and wide.
A Sanity test is used to determine a small section of the application is still working after a minor change.
7. Smoke testing will be conducted to ensure whether the most crucial functions of a program work, but not bothering with finer details. (Such as build verification).
Sanity testing is a cursory testing; it is performed whenever a cursory testing is sufficient to prove the application is functioning according to specifications. This level of testing is a subset of regression testing.
8. Smoke testing is normal health check up to a build of an application before taking it to testing in depth.
Sanity testing is to verify whether requirements are met or not,
checking all features breadth-first.
9. Both sanity tests and smoke tests are ways to avoid wasting time and effort by quickly determining whether an application is too flawed to merit any rigorous testing
