Top 50+ Software Testing Interview Questions
This blog presents the top 50 Software Testing interview questions and answers, divided into elementary and advanced sections. Whether you're a beginner or an experienced professional, this guide will help you strengthen your knowledge and technical expertise.
1. What is Software Testing?
Software Testing is the process of evaluating a software application to identify defects and ensure it meets the specified requirements.
2. What are the different types of Software Testing?
- Functional Testing: Unit, Integration, System, Acceptance Testing
- Non-Functional Testing: Performance, Security, Usability, Compatibility
- Maintenance Testing: Regression, Retesting
3. What is the difference between Verification and Validation?
| Aspect | Verification | Validation |
|---|---|---|
| Definition | Ensures that the software is built correctly. | Ensures that the correct software is built. |
| Method | Static testing (e.g., Reviews, walkthroughs). | Dynamic testing (e.g., Functional Testing). |
| Performed by | Developers, Testers. | Testers, End-users. |
4. What are the different levels of Software Testing?
- Unit Testing – Tests individual components.
- Integration Testing – Tests module interactions.
- System Testing – Tests the entire application.
- User Acceptance Testing (UAT) – Ensures it meets user requirements.
5. What is the difference between Manual and Automation Testing?
| Feature | Manual Testing | Automation Testing |
|---|---|---|
| Execution | Done manually by testers | Performed using tools like Selenium |
| Speed | Slower | Faster |
| Cost | Low initial cost | Higher initial investment but cost-effective in the long run |
6. What is Black Box Testing?
A testing technique where testers evaluate functionality without knowing the internal code structure.
7. What is White Box Testing?
A technique where testers have access to the internal code and test it for security, logic, and structure.
8. What is Grey Box Testing?
A combination of both Black Box and White Box testing, where the tester has partial knowledge of the internal workings.
9. What is a Test Case?
A test case is a document that specifies test steps, expected results, and preconditions for verifying a feature.
10. What are the key components of a Test Case?
- Test Case ID
- Test Scenario
- Preconditions
- Test Steps
- Expected Result
- Actual Result
- Status (Pass/Fail)
11. What is a Test Plan?
A document defining the scope, objectives, resources, and schedule of the testing process.
12. What is a Test Strategy?
A high-level document outlining the general testing approach.
13. What is a Defect in Software Testing?
A defect is an error, flaw, or bug in an application that causes incorrect behavior.
14. What is the Defect Life Cycle?
- New – When a defect is reported
- Assigned – Assigned to a developer
- Open – Developer analyzes the defect
- Fixed – Defect is resolved
- Retest – Tester retests the defect
- Verified – If the fix works
- Closed – If the issue is resolved
15. What is Severity and Priority in Testing?
- Severity: The impact of the defect on functionality (Critical, Major, Minor).
- Priority: The urgency of fixing the defect (High, Medium, Low).
16. What is Automation Testing?
Automation testing has transformed the software development lifecycle, enabling organizations to build, test, and deploy applications more quickly and accurately. Unlike manual testing, which relies on human effort to execute test cases, automation testing utilizes specialized tools and scripts to efficiently handle repetitive and complex test scenarios.
17. What are popular Automation Testing tools?
- DevAssure
- Appium
- JMeter
- Cypress
18. What is Selenium?
Selenium is an open-source automation framework used for testing web applications across different browsers and platforms. It allows testers and developers to write scripts in multiple programming languages such as Python, Java, C#, and JavaScript to automate web interactions.
19. What are the different locators in Selenium?
- ID
- Name
- Class Name
- CSS Selector
- XPath
20. What is Regression Testing?
Regression Testing is a type of software testing that ensures that recent code changes have not negatively affected the existing functionality of an application. It involves re-running previously executed test cases to verify that old features still work correctly after updates, bug fixes, or enhancements.
21. What is Performance Testing?
Performance Testing is a type of software testing that evaluates how an application behaves under different loads, ensuring it performs well in real-world conditions. It helps identify bottlenecks, stability issues, and scalability limitations.
22. What are the types of Performance Testing?
- Load Testing
- Stress Testing
- Scalability Testing
23. What is Security Testing?
Security Testing is a type of software testing that identifies vulnerabilities, threats, and risks in an application to prevent potential cyberattacks and data breaches. It ensures that the system’s data and resources are protected from unauthorized access, manipulation, or destruction.
24. What is Penetration Testing?
Penetration Testing is a type of security testing where ethical hackers simulate real-world cyberattacks to identify vulnerabilities in an application, network, or system before malicious hackers can exploit them.
25. What is API Testing?
API Testing is a type of software testing that focuses on validating the functionality, reliability, security, and performance of Application Programming Interfaces (APIs). It ensures that APIs work as expected, return correct responses, and handle errors properly.
26. What is Agile Testing?
Agile Testing is a continuous testing approach that aligns with Agile software development principles. It focuses on delivering high-quality software through iterative development, continuous feedback, and early defect detection.
27. What is Scrum Testing?
Scrum Testing is a testing approach that aligns with the Scrum framework in Agile development. It involves continuous testing within sprints to ensure software quality while keeping up with rapid development cycles.
28. What is the role of a Tester in DevOps?
In a DevOps environment, a Tester plays a crucial role in ensuring continuous quality, automation, and early defect detection throughout the software development lifecycle (SDLC). Unlike traditional testing, DevOps testing is integrated, automated, and continuous to support CI/CD (Continuous Integration & Continuous Deployment).
29. What is Continuous Integration (CI) in Testing?
Continuous Integration (CI) is a DevOps practice where developers frequently merge their code into a shared repository, triggering automated builds and tests to ensure early defect detection.
30. What is Continuous Deployment (CD)?
Continuous Deployment (CD) is a DevOps practice where every code change that passes automated tests is automatically released to production without manual intervention. It ensures that new features, bug fixes, and updates reach users as quickly as possible.
31. What is Usability Testing?
Usability Testing is a non-functional testing method that evaluates how easily a user can interact with an application. It ensures the product is user-friendly, intuitive, and efficient by identifying usability issues before release.
32. What is Compatibility Testing?
Compatibility Testing is a type of non-functional testing that ensures a software application works seamlessly across different devices, operating systems, browsers, network environments, and hardware configurations.
33. Difference between Retesting and Regression Testing?
- Retesting: Testing the same scenario again after fixing defects.
- Regression Testing: Ensuring new changes don’t affect existing functionality.
34. What is A/B Testing?
A/B testing is nothing but Comparing two versions of a webpage to determine which performs better.
35. What is Exploratory Testing?
Exploratory Testing is a process which involves Testing without predefined test cases.
36. What is Risk-Based Testing?
Prioritizing test cases based on risk and testing them is called Risk-based Testing.
37. What is Data-Driven Testing?
Executing test cases with multiple sets of input data is called Data-Driven testing.
38. What is Boundary Value Analysis?
Boundary Value Analysis (BVA) is a black-box testing technique used to identify defects at the extreme ends of input values (boundaries), where errors are most likely to occur.
39. What is Equivalence Partitioning?
Equivalence Partitioning (EP) is a black-box testing technique that divides input data into groups (partitions) where test cases are expected to behave similarly. Instead of testing every possible input, testers select one representative value from each partition, reducing the number of test cases while maintaining effective coverage.
40. What is Fuzz Testing?
Fuzz Testing is a security and reliability testing technique that involves providing a system with random, malformed, or unexpected inputs to uncover vulnerabilities, crashes, or unexpected behaviors. It helps detect buffer overflows, injection flaws, memory leaks, and other security loopholes before attackers exploit them.
41. What is Monkey Testing?
Monkey Testing is a random testing technique where the application is tested with unexpected, random, or arbitrary inputs to check for crashes, performance issues, or unpredictable behavior. It helps identify edge-case failures and stability issues that structured test cases might miss.
42. What is Smoke Testing?
Smoke Testing is a high-level software testing method that checks whether the basic functionalities of an application work correctly before proceeding with detailed testing. It acts as a quick health check to ensure that the critical features are stable after a new build or deployment.
43. What is Sanity Testing?
Sanity Testing is a focused testing approach that verifies whether a specific bug fix, enhancement, or code change has been implemented correctly without introducing new issues. It is performed after receiving a new build with minor changes to ensure that the affected functionality works as expected before moving to more detailed testing.
44. What is Shift-Left Testing?
Shift-Left Testing is a software testing approach that moves testing earlier (left) in the development lifecycle to detect and fix defects as soon as possible. Instead of waiting for testing at the end of development, testing activities are integrated from the requirement, design, and development phases to improve software quality and reduce costs.
45. What is Model-Based Testing?
Model-Based Testing (MBT) is a software testing approach where test cases are automatically generated from a model that represents the system’s behavior, logic, or requirements. Instead of writing test cases manually, testers create a visual or mathematical model, and test cases are derived systematically from it.
46. What is End-to-End Testing?
End-to-End (E2E) Testing is a testing methodology that validates the entire application flow from start to finish, ensuring that all integrated components work as expected. It simulates real-world user scenarios to test functional, data flow, and performance aspects across multiple systems.
47. What is Compliance Testing?
Compliance Testing (also known as Conformance Testing) is a software testing process that ensures an application, system, or product adheres to industry standards, regulations, and legal requirements. It verifies that the software complies with government laws, security protocols, and business policies to avoid legal risks and ensure safe operations.
48. What is Acceptance Testing?
Acceptance Testing is a software testing process where a system is evaluated to ensure it meets business requirements and is ready for deployment. It validates whether the application works as intended for end users and satisfies stakeholder expectations before release.
49. What is Adhoc Testing?
Adhoc Testing is an informal and unstructured testing approach where testers explore the application without predefined test cases to find defects through random and intuitive interactions. It relies on the tester’s experience, creativity, and curiosity to uncover issues that structured testing might miss.
50. What is Chaos Testing?
Chaos Testing (also known as Chaos Engineering) is a software testing methodology that intentionally introduces failures into a system to test its resilience, reliability, and fault tolerance. It helps identify weaknesses in distributed systems before they cause real-world outages.