ISTQB Interview Questions

Last updated on Nov 07, 2023

ISTQB brings an international standard for software testers. The international software testing  qualification board is an international board who offers globally accepted certification to the learners in the software testing field. Foundation level qualification is aimed at professionals who need to demonstrate the practical knowledge of the fundamental testing concepts. The core principle of designing this article is to help those who are willing to upskill their testing concepts. 

If you go through these ISTQB interview questions and answers fully you can crack any complex interviews. 

Most Frequently Asked ISTQB Interview Questions

1) What is ISTQB?

Ans: The International software testing qualification board (ISTQB) is a standard software testing certification institution. It was first founded in Edinburgh in November 2002 and it's a non-profit test organization.

ISTQB is a Belgium testing organization run by many volunteer test experts around the world.

2) What do you mean by exploratory testing and when does it perform?

Ans: As the name indicates, exploratory testing is nothing but exploring the test case, finding the software, what this software does, whether this software doesn’t do, what this testing does, and what does not work. And it is also a hands-on approach in which testers are involved in minimum planning and maximum executions.

Steps involved in exploratory testing;

  • Guesses
  • Architectural diagrams and use cases
  • Past defects
  • Error handling
  • Discussions
  • Questions and checklists.


This exploratory testing is performed at the time of agile testing or as a final check before the release of the software. This is just a complementary activity during automated regression testing.

3) Name the types of test techniques?

Ans: Test techniques are used to identify the defects and also reduce the number of test cases.

The following are the types of test techniques;

  • Equivalence partitioning
  • Boundary value analysis
  • Decision table testing/ cause-effect graphing
  • State transition tables
  • All pair testing/ orthogonal Array testing
  • Classification free method
  • Use case testing.

4) How these testing techniques perform?

Ans: 1) Equivalence partitioning: It involves grouping of test conditions into various, which are handled the same way.

2) Boundary value analysis: it involves defining boundaries of the partitions and testing for them after.

3) Decision table testing/ graphical cause-effective technique: It involves defining and testing for a different combination of conditions.

4) The transition of table state testing: It involves the identification of all types of valid states and transitions which need to be tested.

5) All pair testing/orthogonal array testing: It involves the identification of various combinations of configuration that need to be tested.

6) Classification tree method: It involves the use of graphical notations to describe the test conditions and combination handled by the test cases.

7) Use case test techniques: It involves the identification of various usage scenarios and then testing accordingly.

5) What type of testing is considered in web testing?

Ans: There are two types of web testing available; 1) performance testing and 2) security testing.

Web testing validating your application accessible through the web. In web testing, one can test for different response codes and error messages depending on web applications.

6) What is the difference between a bug, an error, a detect, and failure?


  • Error: The difference between the actual output of software the true and the correct output.
  • Failure: A failure occurs when the user perceives that a software program ceases to deliver the expected services.
  • Detect: It is the difference between expected and actual results in the context of testing. It is the deviation of the customer requirements.
  • Bug: A programming error or incorrect status helps to run the software properly without causing the whole application to produce incorrect results.

7) Why is software testing is so important?

Ans: The following are the essential reasons;

  • To find detect, fault, errors in software during its development.
  • To ensure the users' or customers' satisfaction and reliability of an application.
  •  Increase the reliability and quality of the software.
  •  Deliver high quality or software applications.

8) What are the different test values?

Ans: There are four levels of testing recommended:

  • Unit testing -> done by developers
  • Integration testing -> Done by testers
  • System testing -> Done by testers
  • Acceptance testing -> done by end-users.

9) What are the different black box testing techniques?

Ans: In Black box testing, internal architecture or implementation of the functionality is NOT known to the tester.

The block box testing techniques are;

  • Equivalence partitioning test techniques
  • Boundary Value Analysis (BVA) test technique
  • Decision table testing
  • State transition testing
  • Use case testing.

10) What is a test plan?

Ans: The test plan is nothing but a contract between customers/ testers and users. The testers should know what will be tested.

  • The project team will be designing and planning the test strategies that balance the test techniques.
  • Without a document test to be done, the test case cannot be verified, analyzation and no test case is not repeatable.
  • A test plan indicates the overall test plan, objectives, and user approach.

ISTQB Training

  • Master Your Craft
  • Lifetime LMS & Faculty Access
  • 24/7 online expert support
  • Real-world & Project Based Learning


11) Name the different test planning techniques?

There are four different test planning techniques available;

  • Acceptance testing
  • System testing
  • Integration testing
  • Unit testing.

12) What information should be included on a bug or defect report?

Ans: A document reporting on any flaw in a component or system that can cause the components or systems to fail to perform its required action is called bug/defect reporting.

       There are 3 ways to create a defect/bug report;

  • Discover defect: Detect the defect before releasing to the customer
  • Report defect: Report the defect to the development team
  • Accept defect: Developer accepts or rejects the bug.

13) Name the types of software testing techniques?

Ans: The following are the different software testing techniques;

  • Manual testing
  • Automation testing
  • Performance testing
  • Security testing
  • Black-box testing
  • White-box testing

14) What is a software testing technique?

Ans: Software testing is a process used for software correctness, check the performance and quality of the software product being developed.

It is the process of executing a program/ application under positive and negative conditions by manual and automated means. It checks for the:

  • Specification
  • Functionality
  • Performance.

15) What are the benefits of ISTQB?

Ans: The main advantages of using ISTQB techniques;

  • The software testing tool is a simple model and easy to manage.
  • Software testing is applicable for small software.
  • Offers early testing involvement
  • The clear relationship between test phases and development phases.
  • Risk and uncertainty are managed.
  • Testing activities and processes are managed.
  • Adaptable to changes.
  • Early client involvement – avoid unrealistic requirements
  • Avoid spending time on useless activities.

16) How do you test the login feature of web applications?

Ans: The possible ways to test the login feature of web applications;

  • Firstly sign in with your valid login detail -> close the web browser -> again reopen the browser -> check whether you are logged in to the system or not.
  • Next is session management -> keep track of user login details -> this is done by using cookies or web sessions.
  • Again sign in and sign out -> go back to the login page -> check you truly logged out.
  • Login -> go back to the login page -> can you see the login page?
  • Sign in one web browser page -> then open the other login page -> check whether you need to sign in again
  • ·Now login -> change the password -> then logout -> you can again log in to the web browser using old login details.

17) What is Acceptance testing?

Ans: The customer writes acceptance tests to determine if the system is doing the right thing. Acceptance tests represent the customer's interests. The acceptance test gives the customer confidence that the application has the required features and that they behave correctly.

18) What is accessibility testing?

Ans: Accessibility testing tool that helps to find the accessibility defects. Debugger mode automated to find the accessibility defects on your website by using the axe chrome extensions.

19) What is agile testing?

Agile testing is a type of software testing technique that follows the agile software development application principles.

Ans: Agile testing these testing activities:

  • Guiding development with concrete examples
  • Asking the question to test ideas and assumption
  • Automated testing and exploratory testing
  • Testing for quality attributes like performance, reliability, and security.

20) What is Adhoc Testing?

Ans: Adhoc testing is a random unscripted software testing method. It is like a "single-use" testing. It is sometimes mixed up as exploratory testing, negative, and monkey testing. However, the meaning of “ad-hoc " is applying test processes that are using hand.

Subscribe to our YouTube channel to get new updates..!


21) What is the application programming interface?

Ans: An API is a set of functions provided by an operating system or other system software. An application program calls the functions to request the service. An API clearly defines how to call functions and what the results are.

22) What is automated testing?

Ans: Automate tests perform repeatable actions on your application and compare expected values with actual results. It uses the software to verify the implementation of tests, which in most cases helps to reduce the test time and simplify the process.

23) What is BETA testing?

Ans: BETA testing is a type of test practice and this is performed by software application development real users in the real-time environment.

  • It is always performed by the customers at their site.
  • It is not be performed by the independent testing team.
  • It is open to the market and the public.
  • ·It is mainly used for software products.
  • It is only a kind of black-box testing.
  • It is also known as field testing.

24) What is bottom-up testing?

Ans: Bottom-up testing uses the incoming input as the for understanding the message.  Comprehension is the process of decoding.

  • Lower level components are combined in clusters that perform a specific software function.
  • A driver mainly coordinates/supports the test case input/output.
  • The bottom-up supports cluster testing
  • In the program structure, the drivers will be removed using the bottom-up technique and also enable clusters to be combined.

25) What is the difference between severity and priority?

Priority Severity
Priority refers to the project and how urgent it is to solve the bugs Severity refers to the bug and how it affects the user’s interaction with the applications.
Priority is set based on changing project factors e.g., the status of the bug, its importance customer side Severity is objectively set based on the direct and indirect impact of the bug and its probability of occurrence
Priority is a dynamic field, should be revised and updated as the project progresses Severity is usually a static field ( the only reason to modify it would be if we learn something new about the bug)

26) What is failure?

Ans: The fault occurs when a fault is executed. This failure finds the inability of software components to perform many functions within the availability of the performance requirements.

27) Mention the difference between validation and verification?


Verification Validation
Verification is to check whether the software conforms to specification Validation is to check whether the software meets the customer requirements
This doesn’t include the code execution This always includes the execution of the program code
This is nothing but the human-involvement type of checking the documents or files It is a computer-based execution of the program

28) What is independent testing and mention its risks?

Ans: Independent testing is nothing tests done by the person who writes it. Test by another person within that team or test done by the person from the independent test team.

Independent testing has some risk;

  • Isolation and lack of communication
  • Interpersonal level
  • Isolation from the border ( business) view
  • Independent testing may become the bottleneck
  • Developers may lose a sense of responsibility and quality.

29) What are the principles of testing?

Ans: The following are the 7 principles of software testing;

Testing helps to find the errors that occur in the software development

Testing doesn’t allow the type of exhaustive testing

Reduce the errors, incompleteness  

  • Clustering is not allowed
  • Produce the effectiveness
  • Testing can be done on the software context
  • Avoid false conclusion: this produces less error/bugs

30) Why software testing is so important?

Ans: The following reasons explain why we need software testing;

  • Reveal faults/failure/ errors
  • Locate faults/errors/failure
  • Show system correctness
  • Improved confidence that the system performs as desired
  • Indicator of system reliability and system quality.

ISTQB Training

Weekday / Weekend Batches


About Author

As a senior technical content writer for HRK tainings, srivalli patchava has a greater understanding of today's data-driven environment, which includes key aspects of data management and IT organizations. She manages the task of creating great content in the areas of software testing, DevOps, Robotic process automation. Connects with her on Linkedin and Twitter.

Upcoming ISTQB Training Online classes

Batch starts on 6th Dec 2023
Mon & Tue (5 Days) Weekday Timings - 08:30 AM IST
Batch starts on 10th Dec 2023
Mon - Fri (18 Days) Weekend Timings - 10:30 AM IST
Batch starts on 14th Dec 2023
Mon & Tue (5 Days) Weekday Timings - 08:30 AM IST
To Top