Top 20+ ISTQB Interview Questions and Answers in 2025

If you're preparing for an International Software Testing Qualifications Board (ISTQB) interview, it's essential to be well-prepared, highlighting the importance of ISTQB Certification for career advancement. ISTQB certifications are globally recognised and can significantly enhance your career prospects in the field of software testing. But an obstacle in the way of aspirants achieving in this field is the complex nature of ISTQB Interview Questions.  

According to Glassdoor, the average base salary for a software testing professional holding ISTQB certifications is 4900 GBP, making the career opportunities more lucrative. This blog will provide a comprehensive list of the top 20+ ISTQB Interview Questions and Answers to help you ace your interview. 

Table of Contents 

1) What is ISTQB? 

2) Importance of ISTQB certifications 

3) Preparation for an ISTQB interview 

4) Top 20+ ISTQB Interview Questions and Answers 

5) Conclusion 

What is ISTQB?   

ISTQB is a non-profit organisation that offers certifications in software testing. ISTQB certifications provide industry-standard recognition of software testing expertise and are widely accepted by employers worldwide. These certifications validate your knowledge and skills in various aspects of software testing, including test design techniques, test management, and test automation. 

Register for the ISTQB Software Testing Foundation training course today and take a step closer to becoming an ISTQB-certified software tester! 

Importance of ISTQB certifications 

ISTQB certifications hold significant importance in the software testing industry. They demonstrate your commitment to professional development and indicate you possess the necessary knowledge and skills to perform software testing effectively. Employers often prefer candidates with ISTQB certifications as it assures them of a certain level of competence and proficiency. 

Additionally, ISTQB certifications can open doors to better job opportunities and higher salaries. These certifications also enable individuals to stay updated with industry trends and best practices, ensuring they possess the necessary skills to excel in their roles. Being part of the ISTQB community allows professionals to network with like-minded individuals, share knowledge, and contribute to the continuous improvement of the software testing field.

Preparation for an ISTQB interview 

Before diving into the interview questions, it's crucial to prepare thoroughly. Listed below are some essential steps to help you in your preparation: 

a) Understanding the job requirements: Familiarise yourself with the job description and requirements of the position you are applying for. This will give you insights into the specific skills and knowledge the employer is seeking. 

b) Reviewing the ISTQB syllabus: The ISTQB syllabus outlines the topics and concepts covered in the certification exams. Review the syllabus relevant to the certification level you are pursuing, ensuring you have a solid understanding of the key concepts. 

c) Practising sample questions: Familiarise yourself with the types of questions typically asked in ISTQB interviews by practising sample questions. This will help you get a sense of the question patterns and improve your ability to provide concise and accurate answers. 

Take your software testing skills to the next level with the ISTQB Advanced Software Test Manager training course. Sign up now! 

Top 20+ ISTQB Interview Questions and Answers   

Now, let's dive into the top 20+ ISTQB interview questions and their corresponding answers: 

Question 1: What is software testing? 

Answer: Software testing is a systematic process of evaluating software to identify defects or errors. It involves executing software components or systems and comparing actual and expected results. Software testing aims to ensure that the software meets the specified requirements, functions correctly, and is reliable. Testing helps identify defects early in the development cycle, improves software quality, and provides confidence in its performance. 

Question 2: What is the difference between verification and validation? 

Answer: Verification and validation are two distinct activities in the software testing process. Verification focuses on evaluating work products, such as requirements, designs, and code, to ensure that they meet specified requirements and standards. It involves reviews, inspections, and walkthroughs to detect and correct errors early in the development process. Validation ensures that the software satisfies the intended use and customer needs. It involves testing the software against user requirements to validate its functionality, performance, and usability. 

Question 3: What is the difference between functional testing and non-functional testing? 

Answer: Functional testing verifies the functional aspects of the software, ensuring that it behaves according to the specified requirements. It focuses on validating features, inputs, outputs, and interactions with the user. Non-functional testing, on the other hand, tests the non-functional aspects of the software, such as performance, security, reliability, and usability. It aims to evaluate how the software performs under various conditions and assess its quality attributes beyond functionality. 

Question 4: What are the different levels of software testing? 

Answer: Software testing can be categorised into different levels based on the scope and objectives of testing. The standard levels include unit testing, integration testing, system testing, and acceptance testing.  

Unit testing involves testing individual units or components of the software. Integration testing focuses on testing interactions between different units or components. System testing verifies the behaviour of the entire system in a controlled environment. Acceptance testing is performed to validate the software against user requirements and ensure its readiness for deployment. 

Question 5: What is regression testing? 

Answer: Regression testing ensures that changes or enhancements to a software product do not introduce new defects or negatively impact existing functionality. It involves retesting the previously tested components and functionalities to ensure they still function as intended after modifications or additions. Regression testing helps maintain the overall quality and stability of the software by uncovering any regressions or unintended consequences of changes. 

Question 6: What are the different black-box testing techniques? 

Answer: Black-box testing techniques involve testing the software without considering its internal structure or implementation details. Common black-box testing techniques include: 

a) Equivalence partitioning, where inputs are divided into classes expected to exhibit similar behaviour. 

b) Boundary value analysis, which focuses on testing the boundaries of input ranges. 

c) Decision table testing, where combinations of conditions and actions are tested. 

d) State transition testing, which validates the behaviour of the software as it transitions between different states. 

Question 7: What is test automation? 

Answer: Test automation is the use of software tools and scripts to automate the execution of tests, compare actual outcomes with expected outcomes, and report test results automatically. It involves creating scripts or test cases that can be executed repeatedly, reducing manual effort and increasing the efficiency of the testing process. Test automation benefits repetitive tasks, regression testing, and large-scale testing efforts. It helps save time, improves test coverage, and enhances the accuracy and reliability of test results. 

Unlock the power of automation in software testing with the ISTQB Advanced Test Automation Engineer course. Register today! 

Question 8: How do you prioritise test cases? 

Answer: Test case prioritisation involves determining the order in which test cases should be executed based on their relative importance and the associated risks. Several factors can be considered for prioritisation, including the criticality of the functionality being tested, the impact of failures on users or business processes, and the likelihood of occurrence of specific scenarios. Prioritising test cases helps ensure that the most critical functionalities are thoroughly tested first, allowing for early detection and resolution of high-risk issues. 

Question 9: What is a test plan? 

Answer: Test plans are documents that entail the approach, objectives, scope, and resources required for testing a software product or project. They serve as roadmaps for the testing effort, providing details on the testing activities, timelines, milestones, and deliverables. A test plan typically includes information about test objectives, test strategies, test environments, test schedules, test deliverables, and risk assessment. It guides the testing team, ensuring that testing is well-organised, comprehensive, and aligned with project goals. 

Question 10: What is a test case? 

Answer: Test cases are a set of conditions or actions designed to validate a specific functionality or aspect of a software application. They describe the inputs, test steps, expected outcomes, and any preconditions or post-conditions for a particular test scenario. Test cases are derived from test requirements or user stories and provide a structured approach to testing. They serve as a documented reference for executing and reproducing tests, ensuring consistency, and facilitating test coverage and traceability. 

Question 11: What is a defect? 

Answer: A defect, also known as a bug or an issue, is an imperfection or deviation in the software resulting in incorrect or unexpected behaviour. Defects can occur due to coding errors, design flaws, or mismatches between software and requirements. Deficiencies can impact the functionality, performance, or usability of the software and may vary in severity and impact. Defects are typically reported, tracked, and managed using defect-tracking tools or systems, and their resolution involves debugging, code fixes, and retesting. 

Question 12: What is exploratory testing? 

Answer: Exploratory testing is an approach where software testers simultaneously execute and design test cases, exploring the software's behaviour without predefined scripts or test plans. Testers use their domain knowledge, experience, and intuition to dynamically create and execute tests based on their observations during testing. Exploratory testing is helpful in uncovering defects, usability issues, and unexpected scenarios that scripted test cases might not cover. It promotes flexibility, creativity, and adaptability in testing. 

Question 13: What is a test harness? 

Answer: A test harness, also known as a test framework, is a collection of tools, libraries, and utilities used to automate and support the execution of tests. It provides a structured and standardised environment for developing, executing, and managing tests. A test harness often includes functionalities for test case creation, test data management, test execution, result reporting, and test environment management. Test harnesses help streamline the testing process, improve test efficiency, and enhance the reproducibility and consistency of test results. 

Question 14: What is load testing? 

Answer: Load testing is a branch of performance testing that evaluates the behaviour of a software application under normal and anticipated peak load conditions. It involves subjecting the software to realistic workloads and measuring its response and performance metrics, such as response time, throughput, and resource utilisation. Load testing helps identify performance bottlenecks, assess the software's scalability and stability, and ensure it can handle the expected user load without degrading performance. 

Question 15: What is the difference between a test case and a test scenario? 

Answer: A test case is a specific instance or example of a test consisting of inputs, actions, and expected outcomes to validate a particular functionality or aspect of the software. It is a detailed step-by-step description of how a specific test should be executed.  

On the other hand, a test scenario refers to a broader set of conditions or situations that need to be tested. It encompasses multiple test cases that cover different aspects or variations of a specific functionality or feature. Test scenarios provide a high-level view of the testing scope, while test cases provide detailed steps to execute within each scenario.


 

Question 16: What is the difference between static testing and dynamic testing? 

Answer: Static and dynamic testing are two different approaches to software testing. Static testing is a type of testing that examines the software without executing it. It focuses on reviewing documents, code, and other artefacts to identify defects or discrepancies. Static testing techniques include reviewing requirements, design documents, and code inspections. 

On the other hand, dynamic testing involves executing the software and observing its behaviour. It aims to validate the functional and non-functional aspects of the software. Dynamic testing techniques include test case execution, regression testing, and usability testing. While static testing can uncover defects early in the development process, dynamic testing provides insights into how the software behaves under real-world conditions. 

Question 17: What is the role of a test leader? 

Answer: A test leader plays a crucial role in managing the testing activities within a project. They are responsible for planning, organising, and coordinating the overall testing effort. The test leader works closely with stakeholders, project managers, and other team members to ensure testing aligns with project objectives. They develop the test strategy, define test objectives, and allocate resources effectively.  

The test leader also oversees test planning, case design, and execution. They monitor the progress of testing, track defects, and communicate testing status and progress to stakeholders. Additionally, the test leader mentors and guides the testing team, ensuring that testing processes and best practices are followed and any issues or risks are addressed promptly. 

Question 18: What is the purpose of a test case template? 

Answer: A test case template is a standardised document used to record the details of a test case. It provides a structured format for documenting the necessary information about a specific test case.  

The purpose of a test case template is to ensure consistency and completeness in test case documentation. It typically includes sections for test case identification, test case description, preconditions, test steps, test data, expected results, and post-conditions. Testers can systematically capture relevant information using a test case template, making reviewing, executing, and maintaining test cases more manageable. It also helps share test cases across the team, promoting collaboration and ensuring that all necessary aspects of a test case are covered. 

Question 19: What is the difference between positive testing and negative testing? 

Answer: Positive and negative testing are complementary approaches to validating software behaviour. Positive testing focuses on verifying that the software functions as expected with valid inputs. It aims to ensure that the software produces the desired outputs and behaves correctly under normal or expected conditions.  

On the other hand, negative testing verifies how the software handles invalid or unexpected inputs or conditions. It involves intentionally testing the software with invalid information, out-of-range values, or exceptional scenarios to ensure it responds appropriately and gracefully handles errors. While positive testing confirms that the software meets the specified requirements, negative testing helps uncover potential vulnerabilities, edge cases, and error-handling capabilities. Positive and negative testing is essential for thorough software testing and comprehensively assesses the software's robustness and reliability. 

Question 20: How do you measure the effectiveness of testing? 

Answer: Measuring testing effectiveness is crucial to assess the quality and coverage of the testing effort. Several metrics can be used to evaluate the effectiveness of testing. Test coverage metrics indicate the percentage of the software or specific requirements covered by test cases, and it helps assess the thoroughness of testing and identify gaps in coverage. The defect detection rate measures the number of defects found during testing relative to the total number of defects present in the software. It provides insights into the efficiency of defect identification.  

Other metrics include the number of defects found in production, test execution and completion rates, test case effectiveness, and customer satisfaction. By analysing these metrics, stakeholders can gauge the effectiveness of testing, identify areas for improvement, and make informed decisions to enhance the overall quality of the software. 

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Question 21: What is the role of a test environment? 

Answer: A test environment plays a crucial role in software testing. It is a setup that mimics the production environment where the software will eventually be deployed. The test environment includes the hardware, software, network configurations, and other dependencies required to execute tests accurately. The role of a test environment is to provide a controlled and realistic setting for testing the software. It ensures the software functions correctly and interacts seamlessly with the underlying infrastructure.  

The test environment should replicate the production environment as closely as possible to uncover any environment-specific issues and validate the software's compatibility, performance, and functionality. The test team is responsible for setting up, configuring, and maintaining the test environment, ensuring its readiness for testing activities, and minimising any discrepancies between the test and production environments. 

Question 22: How do you handle test data management? 

Answer: Test data management involves effectively managing and manipulating data used during software testing. Test data plays a crucial role in validating the software's functionality, performance, and reliability. Handling test data involves several steps. First, test data requirements are identified based on the test scenarios and objectives. Then, suitable test data is generated or obtained from various sources. This data may include valid and invalid inputs, boundary values, and edge cases to cover multiple scenarios. 

Test data should be carefully designed to ensure adequate coverage of test cases and to uncover potential defects. It is essential to handle test data securely, considering privacy and data protection regulations. Test data should be adequately documented, stored, and managed to facilitate test case execution and reusability. Effective test data management helps ensure the accuracy and effectiveness of testing activities and enables testers to validate the software under various real-world scenarios. 

Conclusion   

In conclusion, preparing for an ISTQB interview requires a solid understanding of software testing concepts, hands-on experience, and familiarity with common interview questions. By reviewing the provided top 20+ ISTQB Interview Questions and Answers and thoroughly preparing, you can increase your chances of performing well in the interview and securing the desired position. Good luck with your interview! 

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