Sanity vs Smoke Testing

Smoke testing and sanity testing are both quick testing approaches used to determine whether software is ready for more detailed testing.

Although they are often confused, they have different purposes:

• Smoke testing checks whether the overall build is stable enough for testing.

• Sanity testing checks whether a specific feature or area is working correctly after a change or fix.

Both are usually focused, time-saving checks rather than complete testing of the application.

Smoke Testing

Smoke testing is a broad and shallow test performed on a new build to check whether the major functions of the application are working.

The main question is:

"Is this build stable enough to continue testing?"

Example

Suppose a new build of an e-commerce application is released.

A tester may quickly verify:

1. Application opens successfully.

2. User can log in.

3. Products can be searched.

4. Product details can be opened.

5. Product can be added to the cart.

6. Checkout page can be opened.

If major functionality is completely broken, the build may be rejected for further testing.

If the basic functions work, the testing team can continue with more detailed testing.

Sanity Testing

Sanity testing is a narrow and focused check performed after a specific change, bug fix, or small update.

The main question is:

"Does the changed or fixed area now work correctly?"

Example

Suppose a developer fixes a problem where users could not apply a discount code during checkout.

The tester may perform sanity testing around:

1. Entering a valid discount code.

2. Applying the discount.

3. Checking whether the discount amount is calculated correctly.

4. Verifying the updated order total.

5. Checking that invalid discount codes are handled correctly.

The tester may not retest the entire application at this stage because the purpose is to quickly verify the affected area.

Smoke Testing vs Sanity Testing

1. Scope

Smoke Testing

• Broad and shallow.

• Covers major or critical functionality.

• Checks different areas of the application at a basic level.

Sanity Testing

• Narrow and focused.

• Concentrates on a specific feature, module, or affected area.

• Checks whether a particular change or fix works correctly.

2. Purpose

Smoke Testing

• Determines whether the build is stable enough for further testing.

• Helps prevent the team from spending time testing a fundamentally broken build.

Sanity Testing

• Determines whether a specific change or fix is working as expected.

• Helps confirm that the affected functionality is ready for further testing.

3. When It Is Performed

Smoke Testing

• Usually performed when a new build is received.

• Often performed before detailed testing begins.

Sanity Testing

• Usually performed after a bug fix, small change, or limited update.

• Often performed before broader regression testing.

4. Testing Approach

Smoke Testing

• Tests multiple important areas.

• Focuses on basic functionality.

• Does not go deeply into individual features.

Sanity Testing

• Tests a smaller area.

• Focuses more deeply on the changed functionality.

• May also check closely related functionality.

5. Example

Smoke Testing:

"Can users log in, search for products, add products to the cart, and reach checkout?"

Sanity Testing:

"The checkout discount issue was fixed. Does applying a discount now work correctly?"