Software Testing Interview Questions

If you are appearing for a technical round of interview for Software Testing, here’s a list of the top 97 interview questions with answers to help you prepare.

Last updated: Dec 12, 2021

Q. 1: What is Exploratory Testing?

Exploratory testing is a hands-on approach in which testers are involved in minimum planning and maximum test execution. The planning involves the creation of a test charter, a short declaration of the scope of a short (1 to 2 hour) time-boxed test effort, the objectives and possible approaches to be used. The test design and test execution activities are performed in parallel typically without formally documenting the test conditions, test cases or test scripts. This does not mean that other, more formal testing techniques will not be used. For example, the tester may decide to use boundary value analysis but will think through and test the most important boundary values without necessarily writing them down. Some notes will be written during the exploratory-testing session so that a report can be produced afterward.

Q. 2: What is "use case testing"?

In order to identify and execute the functional requirement of an application from start to finish “use case” is used and the techniques used to do this is known as "Use Case Testing."

Q. 3: What is the difference between the STLC (Software Testing Life Cycle) and SDLC (Software Development Life Cycle)?

SDLC deals with development/coding of the software while STLC deales with validation and verification of the software.

Q. 4: What is traceability matrix?

The relationship between test cases and requirements is shown with the help of a document. This document is known as a traceability matrix.

Q. 5: What is Equivalence partitioning testing?

Equivalence partitioning testing is a software testing technique which divides the application input test data into each partition at least once of equivalent data from which test cases can be derived. By this testing method, it reduces the time required for software testing.

Q. 6: What is white box testing and list the types of white box testing?

White box testing technique involves selection of test cases based on an analysis of the internal structure (Code coverage, branches coverage, paths coverage, condition coverage, etc.) of a component or system. It is also known as Code-Based testing or Structural testing. Different types of white box testing are

Q. 7: In white box testing, what do you verify?

In white box testing following steps are verified.

Q. 8: What is black box testing? What are the different black box testing techniques?

Black box testing is the software testing method which is used to test the software without knowing the internal structure of code or program. This testing is usually done to check the functionality of an application. The different black box testing techniques are

Q. 9: What is the difference between static and dynamic testing?

Q. 10: What are verification and validation?

Verification is a process of evaluating software at the development phase. It helps you to decide whether the product of a given application satisfies the specified requirements. Validation is the process of evaluating software at the after the development process and to check whether it meets the customer requirements.

Q. 11: What are the different test levels?

There are four test levels

Q. 12: What is Integration testing?

Integration testing is a level of software testing process, where individual units of an application are combined and tested. It is usually performed after unit and functional testing.

Q. 13: What Test Plans consists of?

Test design, scope, test strategies, approach are various details that Test plan document consists of.

Q. 14: What is the difference between UAT (User Acceptance Testing) and System testing?

Q. 15: Mention the difference between Data Driven Testing and Retesting?

Q. 16: What are the valuable steps to resolve issues while testing?

Q. 17: What is the difference between test scenarios, test cases, and test script?

Difference between test scenarios and test cases is that

Q. 18: What is Latent defect?

Latent defect: This defect is an existing defect in the system which does not cause any failure as the exact set of conditions has never been met

Q. 19: What are the two parameters which can be useful to know the quality of test execution?

To know the quality of test execution, we can use two parameters

Q. 20: What is the function of the software testing tool "phantom"?

Phantom is a freeware and is used for windows GUI automation scripting language. It allows us to take control of windows and functions automatically. It can simulate any combination of keystrokes and mouse clicks as well as menus, lists and more.

Q. 21: Explain what Test Deliverables is?

Test Deliverables are a set of documents, tools and other components that have to be developed and maintained in support of testing.

There are different test deliverables at every phase of the software development lifecycle

Q. 22: What is mutation testing?

Mutation testing is a technique to identify if a set of test data or test case is useful by intentionally introducing various code changes (bugs) and retesting with original test data/ cases to determine if the bugs are detected.

Q. 23: What all things you should consider before selecting automation tools for the AUT?

Q. 24: How will you conduct Risk Analysis?

For the risk analysis following steps need to be implemented

Q. 25: What are the categories of debugging?

Categories for debugging

Q. 26: What is fault masking explain with example?

When the presence of one defect hides the presence of another defect in the system, it is known as fault masking


If the "Negative Value" cause a firing of unhandled system exception, the developer will prevent the negative values input. This will resolve the issue and hide the defect of unhandled exception firing.

Q. 27: Explain what Test Plan is? What is the information that should be covered in Test Plan?

A test plan can be defined as a document describing the scope, approach, resources, and schedule of testing activities and a test plan should cover the following details.

Q. 28: How can you eliminate the product risk in your project?

It helps you to eliminate product risk in your project, and there is a simple yet crucial step that can reduce the product risk in your project.

Q. 29: What is the common risk that leads to project failure?

The common risk that leads to a project failure are

Q. 30: On what basis you can arrive at an estimation for your project?

To estimate your project, you have to consider the following points

Q. 31: Explain what is testing type and what are the commonly used testing type?

To get an expected test outcome, a standard procedure is followed which is referred to as Testing Type.

Commonly used testing types are

Q. 32: While monitoring your project what all things you have to consider?

The things that have to be taken in considerations are

Q. 33: What are the common mistakes which create issues?

Q. 34: What does a typical test report contain? What are the benefits of test reports?

A test report contains the following things:

The benefits of test reports are:

Q. 35: What is test management review and why it is important?

Management review is also referred to as Software Quality Assurance or SQA. SQA focusses more on the software process rather than the software work products. It is a set of activities designed to make sure that the project manager follows the standard process. SQA helps test manager to benchmark the project against the set standards.

Q. 36: What are the best practices for software quality assurance?

The best practices for an effective SQA implementation is

Q. 37: When is RTM (Requirement Traceability Matrix) prepared?

RTM is prepared before test case designing. Requirements should be traceable from review activities.

Q. 38: What is the difference between Test matrix and Traceability matrix?

Test Matrix: Test matrix is used to capture actual quality, effort, the plan, resources and time required to capture all phases of software testing

Traceability Matrix: Mapping between test cases and customer requirements is known as Traceability Matrix

Q. 39: In manual testing what are stubs and drivers?

Both stubs and drivers are part of incremental testing. In incremental testing, there are two approaches namely bottom-up and top-down approach. Drivers are used in bottom-up testing and stub is used for a top-down approach. In order to test the main module, the stub is used, which is a dummy code or program.

Q. 40: What is the step you would follow once you find the defect?

Once a defect is found you would follow the step

Q. 41: Explain what is "Test Plan Driven" or "Key Word Driven" method of testing?

This technique uses the actual test case document developed by testers using a spreadsheet containing special "key Words". The key words control the processing.

Q. 42: What is the DFD (Data Flow Diagram)?

When a "flow of data" through an information system is graphically represented, then it is known as Data Flow Diagram. It is also used for the visualization of data processing.

Q. 43: Explain what LCSAJ is?

LCSAJ stands for ‘linear code sequence and jump.’ It consists of the following three items

Q. 44: Explain what N+1 testing is?

The variation of regression testing is represented as N+1. In this technique, the testing is performed in multiple cycles in which errors found in test cycle ‘N’ are resolved and re-tested in test cycle N+1. The cycle is repeated unless there are no errors found.

Q. 45: What is Fuzz testing and when it is used?

Fuzz testing is used to detect security loopholes and coding errors in software. In this technique, random data is added to the system in an attempt to crash the system. If vulnerability persists, a tool called fuzz tester is used to determine potential causes. This technique is more useful for bigger projects but only detects a major fault.

Q. 46: Mention what the main advantages of statement coverage metric of software testing are?

The benefit of statement coverage metric is that

Q. 47: How to generate test cases for "replace a string" method?

Q. 48: How will you handle a conflict amongst your team members?

Q. 49: Mention what are the categories of defects?

Mainly there are three defect categories

Q. 50: Explain how does a test coverage tool work?

The code coverage testing tool runs parallel while performing testing on the actual product. The code coverage tool monitors the executed statements of the source code. When the final testing is done, we get a complete report of the pending statements and also get the coverage percentage.

Q. 51: Mention what the difference between a "defect" and a "failure" in software testing is?

In simple terms when a defect reaches the end customer, it is called a failure while the defect is identified internally and resolved; then it is referred to as a defect.

Q. 52: Explain how to test documents in a project that span across the software development lifecycle?

The project span across the software development lifecycle in the following manner

Q. 53: Explain which test cases are written first black boxes or white boxes?

Black box test cases are written first as to write black box test cases; it requires project plan and requirement document all these documents are easily available at the beginning of the project. While writing white box test cases requires more architectural understanding and is not available at the start of the project.

Q. 54: Explain what the difference between latent and masked defects is?

Q. 55: Mention what bottom-up testing is?

Bottom-up testing is an approach to integration testing, where the lowest level components are tested first, then used to facilitate the testing of higher level components. The process is repeated until the component at the top of the hierarchy is tested.

Q. 56: Mention what the different types of test coverage techniques are?

Different types of test coverage techniques include

Q. 57: Mention what the meaning of breath testing is?

Breath testing is a test suite that exercises the full functionality of a product but does not test features in detail

Q. 58: Explain what the meaning of Code Walk Through is?

Code Walk Through is the informal analysis of the program source code to find defects and verify coding techniques

Q. 59: Mention what the basic components of defect report format are?

The essential components of defect report format include

Q. 60: Mention what the purpose behind doing end-to-end testing is?

End-to-end testing is done after functional testing. The purpose behind doing end-to-end testing is that

Q. 61: Explain what it means by test harness?

A test harness is configuring a set of tools and test data to test an application in various conditions, and it involves monitoring the output with expected output for correctness.

Q. 62: Explain in a testing project what testing activities would you automate?

In testing project testing activities, you would automate are

Q. 63: What is the MAIN benefit of designing tests early in the life cycle?

It helps prevent defects from being introduced into the code.

Q. 64: What is risk-based testing?

Risk-based Testing is the term used for an approach to creating a Test Strategy that is based on prioritizing tests by risk. The basis of the approach is a detailed risk analysis and prioritizing of risks by risk level. Tests to address each risk are then specified, starting with the highest risk first.

Q. 65: What is the KEY difference between preventative and reactive approaches to testing?

Preventative tests are designed early; reactive tests are designed after the software has been produced.

Q. 66: What is the purpose of exit criteria?

The purpose of exit criteria is to define when a test level is completed.

Q. 67: What determines the level of risk?

The likelihood of an adverse event and the impact of the event determine the level of risk.

Q. 68: When is used Decision table testing?

Decision table testing is used for testing systems for which the specification takes the form of rules or cause-effect combinations. In a decision table, the inputs are listed in a column, with the outputs in the same column but below the inputs. The remainder of the table explores combinations of inputs to define the outputs produced.

Q. 69: Why we use decision tables?

The techniques of equivalence partitioning and boundary value analysis are often applied to specific situations or inputs. However, if different combinations of inputs result in different actions being taken, this can be more difficult to show using equivalence partitioning and boundary value analysis, which tend to be more focused on the user interface. The other two specification-based techniques, decision tables, and state transition testing are more focused on business logic or business rules. A decision table is a good way to deal with combinations of things (e.g., inputs). This technique is sometimes also referred to as a 'cause-effect' table. The reason for this is that there is an associated logic diagramming technique called 'cause-effect graphing' which was sometimes used to help derive the decision table

Q. 70: What is the MAIN objective when reviewing a software deliverable?

To identify defects in any software work product.

Q. 71: Which of the following defines the expected results of a test? Test case specification or test design specification.

Test case specification defines the expected results of a test.

Q. 72: As part of which test process do you determine the exit criteria?

The exit criteria are determined on the bases of 'Test Planning'.

Q. 73: What is Alpha testing?

Pre-release testing by end user representatives at the developer's site.

Q. 74: What is beta testing?

Testing performed by potential customers at their own locations.

Q. 75: Mention what the difference between Pilot and Beta testing is?

The difference between a pilot and beta testing is that pilot testing is actually done using the product by the group of users before the final deployment, and in beta testing, we do not input real data, but it is installed at the end customer to validate if the product can be used in production.

Q. 76: Given the following fragment of code, how many tests are required for 100% decision coverage?

if width > length 
  then biggest_dimension = width
    if height > width 
      thenbiggest_dimension = height 
else biggest_dimension = length
  if height > length 
    then biggest_dimension = height 

Q. 77: What is the difference between Testing Techniques and Testing Tools?

Testing technique: – Is a process for ensuring that some aspects of the application system or unit functions properly there may be few techniques but many tools.

Testing Tools: – Is a vehicle for performing a test process. The tool is a resource to the tester, but itself is insufficient to conduct testing

Q. 78: What is component testing?

Component testing, also known as unit, module, and program testing, searches for defects in and verifies the functioning of software (e.g., modules, programs, objects, classes, etc.) that are separately testable. Component testing may be done in isolation from the rest of the system depending on the context of the development life cycle and the system. Most often stubs and drivers are used to replace the missing software and simulate the interface between the software components simply. A stub is called from the software component to be tested; a driver calls a component to be tested.

Q. 79: What is functional system testing?

Testing the end to end functionality of the system as a whole is defined as a functional system testing.

Q. 80: What are the benefits of Independent Testing?

Independent testers are unbiased and identify different defects at the same time.

Q. 81: What are the different Methodologies in Agile Development Model?

There are currently seven different agile methodologies that I am aware of:

Q. 82: What is random/monkey testing? When is it used?

Random testing is often known as monkey testing. In such type of testing data is generated randomly often using a tool or automated mechanism. With this randomly generated input, the system is tested, and results are analyzed accordingly. These testing are less reliable; hence it is normally used by the beginners and to see whether the system will hold up under adverse effects.

Q. 83: Which of the following are valid objectives for incident reports?

Q. 84: What are the Structure-based (white-box) testing techniques?

Structure-based testing techniques (which are also dynamic rather than static) use the internal structure of the software to derive test cases. They are commonly called ‘white-box’ or ‘glass-box’ techniques (implying you can see into the system) since they require knowledge of how the software is implemented, that is, how it works. For example, a structural technique may be concerned with exercising loops in the software. Different test cases may be derived to exercise the loop once, twice, and many times. This may be done regardless of the functionality of the software.

Q. 85: When should “Regression Testing” be performed?

After the software has changed or when the environment has changed Regression testing should be performed.

Q. 86: What is negative and positive testing?

A negative test is when you put in an invalid input and receives errors. While positive testing is when you put in a valid input and expect some action to be completed in accordance with the specification.

Q. 87: What is the difference between re-testing and regression testing?

Re-testing ensures the original fault has been removed; regression testing looks for unexpected side effects.

Q. 88: What are the Experience-based testing techniques?

In experience-based techniques, people’s knowledge, skills, and background are a prime contributor to the test conditions and test cases. The experience of both technical and business people is important, as they bring different perspectives to the test analysis and design process. Due to previous experience with similar systems, they may have insights into what could go wrong, which is very useful for testing.

Q. 89: When should testing be stopped?

It depends on the risks for the system being tested. There are some criteria based on which you can stop testing.

Q. 90: What are semi-random test cases?

Semi-random test cases are nothing, but when we perform random test cases and do equivalence partitioning to those test cases, it removes redundant test cases, thus giving us semi-random test cases.

Q. 91: What is V-Model?

A software development model that illustrates how testing activities integrate with software development phases.

Q. 92: What is maintenance testing?

Triggered by modifications, migration or retirement of existing software.

Q. 93: What is test coverage?

Test coverage measures in some specific way the amount of testing performed by a set of tests (derived in some other way, e.g., using specification-based techniques). Wherever we can count things and can tell whether or not each of those things has been tested by some test, then we can measure coverage.

Q. 94: What is DRE?

In order to measure test effectiveness, a powerful metric is used to measure test effectiveness known as DRE (Defect Removal Efficiency) From this metric we would know how many bugs we have found from the set of test cases. The formula for calculating DRE is

DRE=Number of bugs while a testing/number of bugs while testing + number of bugs found by a user

Q. 95: What are Test comparators?

Is it really a test if you put some inputs into some software, but never look to see whether the software produces the correct result? The essence of testing is to check whether the software produces the correct result and to do that, and we must compare what the software produces to what it should produce. A test comparator helps to automate aspects of that comparison.

Q. 96: What is Boundary value testing?

Test boundary conditions on, below and above the edges of input and output equivalence classes. For instance, let say a bank application where you can withdraw maximum Rs.20,000 and a minimum of Rs.100, so in boundary value testing we test only the exact boundaries, rather than hitting in the middle. That means we test above the maximum limit and below the minimum limit.

Q. 97: What is Rapid Application Development?

Rapid Application Development (RAD) is formally a parallel development of functions and subsequent integration. Components/functions are developed in parallel as if they were mini projects, the developments are time-boxed, delivered, and then assembled into a working prototype. This can very quickly give the customer something to see and use and to provide feedback regarding the delivery and their requirements. Rapid change and development of the product are possible using this methodology. However the product specification will need to be developed for the product at some point, and the project will need to be placed under more formal controls before going into production.