Career Advice

Top 40 Software Testing Interview Questions (And Answers)

John Smith

As an integral part of software development, Software Testers are in high demand and are expected to experience tremendous growth in the coming years. Yet, to become a Software Tester, you’ll have to go through a competitive process and answer some challenging Software Testing interview questions.

We’ve compiled a list of some of the top Software Testing interview questions to help get you started and outmatch other candidates. These questions are designed for people who have basic knowledge of Software Testing, as well as more experienced Testers.

We’ll cover:

Software Testing interview questions for freshers

1. What is Software Testing?

Software Testing is the process of evaluating and verifying the functionality of software products or apps to ensure they meet expected requirements and are free from defects. This is a basic question that every candidate applying for a Software Testing position should be able to answer.

2. What are some of the top qualities of a good Software Tester?

A good Software Tester will need to have an analytical mindset to identify the different types of tests needed to validate software functionalities and the curiosity to approach it from different angles, to see what could break it. They should be able to scrutinise software with the greatest attention to detail, to identify defects even in the most seemingly high-quality software.

3. Explain some of the main different types of testing

You should be able to explain some of the main different types of software testing, as you will likely find yourself using a variety of these in your day-to-day role. This could include the following:

Testing typeDescription
Integration TestingAlso known as I&T, integration testing tests individual components of a system combined, to ensure they work as a whole.
Performance TestingPerformance testing ensures the software functions in line with user requirements, such as checking response time and stability under a high workload.
Regression TestingRegression testing checks that existing features and functionalities work following updates to code.
Security TestingSecurity testing focuses on software security, attempting to break the software and gain access to confidential data. This is particularly important for web-based apps, such as banking.
Smoke TestingSmoke testing is one of the most basic testing types, making sure that the software does not crash when it is started up. Originally, the name comes from hardware testing, where you would plug in a device and check to see if it smokes.
Stress TestingStress testing puts a heavy load on software to make sure it doesn’t break when under pressure, such as a high number of requests at one time.
Unit TestingUnit testing is a programmatic test that ensures a single unit of code functions correctly. A unit test should be automated and easily repeatable.
Usability TestingUsability testing checks how usable a software is. This type of testing usually involves a sample group of end-users who use the software and provide feedback.
User-Acceptance TestingUser-Acceptance is typically the final test before going live that checks the software meets user requirements.

4. What are the seven principles of Software Testing?

There are seven different principles of Software Testing, which include:

5. Define end-to-end testing

End-to-end testing refers to the practice of testing a software system from the start to the finished project, ready for the end-user. This means the Tester would download the software, open and use it just like a user would – giving them the chance to test it with all dependencies and integrations, and putting it under the ultimate test in a real-life environment.

6. What is an API? And why would you use one in Software Testing?

API stands for Application Programming Interface and refers to how two or more computer programmes, or software components, communicate with each other using requests and responses. One use of API is to collect data required for an application. Let’s take a currency exchange app as an example. Instead of creating the tech to collect the exchange rates yourself, you could request it from the exchange rates API.

7. What are test scenarios, scripts and cases?

Test CaseA test case in Software Testing is a set of actions carried out on a system to ensure it meets software requirements and functions as intended.
Test ScenarioA test scenario consists of a series of test cases that cover the end-to-end functionality of an application. It will include a detailed overview of what tests are required.
Test ScriptsTest scripts provide an outline of the steps to be taken to ensure a system works as expected.

8. What is a test environment?

A test environment refers to the hardware, software and network used to run tests. A test environment is designed to replicate the actual hardware that will be used to run the software once released.

9. What is test coverage?

Test coverage measures how much of your test cases are covering application code. A good test coverage goal is 80%, as any more than this could be costly without much additional benefit. To calculate test coverage, you will need to determine how many requirements there are, how many tests are created and how many are executed. A test coverage tool will measure how much of the programme’s source code is covered as a percentage.

There are a few different types of test coverage techniques, such as block, brance, path and function. You should be able to give a top-level description of these, in case it comes up during your interview.

10. Tell me the difference between black-box, white-box and grey-box testing

Testing typeDescription
Black-Box TestingBlack-box testing is used in acceptance and system testing, only testing the external behaviour of the programme, rather than software functions.
White-Box TestingWhite-box testing is typically used in integration and unit testing, and takes internal workings into consideration – unlike black-box.
Grey-Box TestingAs the name suggests, grey-box testing uses a combination of black and white testing methods, taking into account the end product as well as its internal workings.

11. What are the benefits of Automation Testing?

Automation Testing refers to the automation of human/manual testing processes and enables Testers to complete a wider test coverage in a short time sprint. Since this is now becoming increasingly popular in Agile and DevOps software environments, you will likely be questioned on this during your Software Testing interview.

12. What’s the difference between bugs, defects and errors in Software Testing?

BugsA bug is an error in the software, which causes it to malfunction, typically caused by a coding error. Bugs are submitted by Developers and detected prior to product release.
DefectsA defect refers to a system error that means the software cannot function as intended. There are three types of defect: Wrong – incorrect implementation of requirements Missing – a specification has not been implemented Extra – a specification has been implemented that was not required by the end-user
ErrorsErrors refer to problems with the code itself, which are commonly caused by the Developers not understanding the requirements.

Fun fact: The name ‘bug’ originated from the first bug ever found, where an actual insect was stuck in malfunctioning hardware.

13. What are latent and masked defects?

Latent DefectLatent defects are hidden defects, software flaws, that have not yet been detected, and cannot be found until a specific task is performed.
Masked DefectMasked defects are defects that cannot be discovered yet as they are hidden behind another portion of defected code. Only once this defect is detected, can the masked defect be identified.

14. Provide some examples of Software Testing tools

Working as a Software Tester, you will be required to use a variety of software testing tools. Although each organisation will have its own preference, it’s a good idea to get familiar with some of the most popular tools, their uses and benefits, such as:

15. What should be included in a test plan?

A test plan is a document that is monitored by the Testing Manager and provides an outline of the entire test process, including what was tested, when, how and why. A test plan must include the test strategy, objectives, schedule, estimations, deadlines and the resources required.

16. What should be included in a test report?

A test report is a document that summarises testing objectives, activities and results. The main goal of creating a test report is to help Product Managers and Developers make a decision about whether a product is ready to release.

17. What are test deliverables?

Test deliverables, also known as test artefacts, are any by-products generated while conducting tests, such as documents, tools and equipment. These are shared with stakeholders and team members across the entire SDLC.

18. What are the five types of debugging?

Debugging has five different categories, including brute force, backtracking, cause elimination, fault tree analysis and programme slicing. We recommend taking the time to understand these categories so that you can talk about them during your Software Testing interview.

19. What are some of the most common testing mistakes that result in major issues?

We are all human and mistakes happen, however, this can have detrimental outcomes in Software Testing. Some of the most common mistakes that happen in Software Testing include:

Although these may not seem significant, these small mistakes can lead to major issues down the line. It’s important to understand what impact errors can have on product quality and release time.

20. Explain what a user story is and why it is used in Software Testing

A user story is a persona created to put Testers and Developers in the shoes of the end-user, fully understand their requirements and create an aligned product. A user story will often contain real names, characteristics, pain points and aim to recreate a real-life interaction with the software.

21. What is A/B testing?

A/B testing, also known as split testing, is an unbiased controlled experiment where two varied samples (A and B) are tested and compared. In Software Testing, the two samples would be two different versions of the software or new functionalities.

22. What does SPICE stand for?

SPICE (Software Process Improvement and Capability Determination) is an international framework for assessing the efficiency and effectiveness of the development process. This is a common Software Testing interview question that is bound to crop up, so you should be ready to answer this and provide examples of how SPICE can be used!

23. What is sanity testing?

Sanity testing is a subset of regression testing that ensures an application functions as expected after code changes. Sanity testing acts as a checkpoint to decide whether testing can continue. This is an undocumented process that focuses purely on the functionality of the app.

24. What steps would you take to resolve issues while testing?

When it comes to resolving issues while testing, there are three main things to remember. Firstly, keep a record of everything and track all issues you encounter. Next, reporting is key. It’s always recommended to inform higher management about the problem you find. And, finally, regulate issue management by implementing processes and sticking to them.

Software Testing interview questions and answers for more experienced Testers

1. What is boundary value analysis?

Boundary value analysis is a black-box technique used in Software Testing. It involves testing between the two extreme ends or boundaries of partitions, since values closer to the boundary have a higher probability of returning errors.

2. How much testing do you need to do?

Exhaustive testing is impossible, as is proving the complete absence of errors. As a Tester, you should select the test cases that will be most likely to find errors rather than trying to find them all (as you won’t be able to). Once you are happy with the software and are confident it will work as expected, you have done enough testing and can release the product.

3. What is the Software Testing Life Cycle?

The Software Testing Life Cycle, or STLD, are the steps or activities used to test software applications to ensure a high-quality product at the end. As an experienced Software Testing professional, you should be able to explain each stage in detail if required.

4. Define function and non-functional testing

Functional TestingFunctional testing is a type of black-box testing method that looks at the software’s functional requirements, making sure it fulfils these and solves the end-user’s problems.
Non-Functional TestingNon-functional testing focuses on qualities that have been specifically outlined by the client, such as performance or usability.

5. What should be included in a bug report?

A bug report contains a record of the Tester’s observations that may be helpful to Developers or management. A bug report should include a title, description of the bug, the product version, status of the bug, steps to reproduce the bug, who the bug is being assigned to and its resolution.

6. What is TDD?

TDD stands for Test-Driven-Development and is an agile software development methodology that involves the creation of unit test cases before writing the code. It is a process that relies on iterative development in a short cycle, thus creating code with fewer bugs.

7. What is cross-browser testing?

Cross-browser testing is part of the quality assurance process and ensures that a web-based app functions properly across different browsers and devices, such as Google Chrome, Safari and Internet Explorer.

8. Provide a list of the possible HTTP status codes that a server can return, and what they mean.

HTTP status codes indicate whether an HTTP request has been completed successfully. There are five different possible HTTP status code responses, including:

Find out more about the meaning of these various codes to help you practice answering this possible Software Testing interview question.

9. What do low, medium and high severity bugs indicate?

A bug can be assigned a severity rating from low to high. Here is an outline of what each severity type would look like:

LowSoftware may have user interface bugs and some accessibility issues. The defect is an issue, but can be left until more serious defects have been fixed.
MediumThe defects should be dealt with in the regular course of the development activities, however, it is not urgent.
HighThe software at this level of severity will likely be crashing under high workloads or specific user actions and could be exposing sensitive data, thus revealing high-priority security problems that must be dealt with as soon as possible.

As an experienced Software Tester, you should be able to identify each level of severity and apply it to real-life situations, and discuss this with interviewers confidently.

10. What is Alpha and Beta testing?

Alpha testing belongs to the user acceptance testing phase, where the objective is to find bugs before releasing the product to customers. Whereas, Beta testing is the user acceptance  testing that takes place after Alpha when users are interacting with the software in a real environment. Beta testing is essential for getting feedback from real users using the software.

11. What is a test matrix?

A test matrix is a testing tool that is used to present the quality, effort, plan and resources required to complete the entire process of Software Testing, the testing phase of the SDLC.

12. What is a Requirement Traceability Matrix?

A Requirement Traceability Matrix, or RTM for short, is a document that matches test cases with custom requirements. A RTM is usually presented in the form of a table and contains all user requirements and artefacts from the project.

13. Explain the difference between validation and verification in Software Testing

Validation and Verification are both parts of the V Model in Software Testing, which associate a testing phase with the appropriate development stage. Here is the difference between the two:

VerificationVerification is a process that ensures the software meets quality standards and the specification. Verification is an objective process and a type of static testing, since you test the software without actually using it, through code walkthroughs and reviews.
ValidationValidation is a process that checks whether the software functionality meets customer requirements and is done at the end of the development process after verifications are complete. Validation is a more subjective process in comparison to verification, and is a type of dynamic testing as it is tested whilst running in a test environment.

14. What is confirmation testing?

Confirmation testing takes software testing to the next level, to confirm whether previously reported bugs have been fixed. It can also be known as retesting. You should be confident in explaining what confirmation testing is and a scenario where you may need to perform this.

15. What is the defect life cycle?

The defect, or big, lifecycle follows all the stages a bug goes through. Starting as a new bug when first detected, to ultimately being resolved. The defect life cycle steps are as follows:

16. What is defect cascading?

Defect cascading is when one defect leads to a trickle effect, where more defects are triggered. If this occurs and goes undetected, it can cause serious issues later in the production process.

How to prepare for a Software Testing interview

Once you’ve mastered all the technical aspects of the Software Testing interview questions, it’s time to get started on your technique. We recommend the STAR method, an interview-answering technique that helps you provide a structured answer to your employer’s questions. Read all about the STAR interview method.

Looking for more interview advice? Read our top tips on how to ace video interviews and prepare for a strength-based interview.

Software Testing is an exciting role, but you’ll need to make sure you get plenty of practice with your Software Testing interview questions to beat the competition. So, read through these questions, make some notes and get in front of the mirror for some preparation. Good luck!

Could Software Testing be the job for you? Check out the FDM Software Testing Graduate Programme for more information or get in touch with our team.