Manual testing interviews check whether you understand the testing process, can write clear test cases and bug reports, and know how testing fits into Agile teams. These 30 questions are the ones freshers and testers with up to two years of experience hear most, with answers and examples you can adapt.
Not sure whether to start with manual or automation? Read manual testing vs automation testing first.
Testing fundamentals
1. What is software testing?
Checking that software works as expected and finding defects before users do. It covers both verification (are we building the product right?) and validation (are we building the right product?).
2. What are the seven testing principles?
- Testing shows the presence of defects, not their absence.
- Exhaustive testing is impossible.
- Early testing saves time and money.
- Defects cluster in a few modules.
- The pesticide paradox: repeating the same tests stops finding new bugs.
- Testing depends on context.
- Absence of errors is a fallacy if the product does not meet user needs.
3. What is the STLC?
The Software Testing Life Cycle: requirement analysis, test planning, test case design, test environment setup, test execution, and test closure with a summary report.
4. Verification vs validation?
Verification reviews documents, designs and code without running the software (reviews, walkthroughs). Validation runs the software to check it meets user needs (functional and acceptance testing).
5. Error, defect, bug and failure?
A person makes an error, which introduces a defect (often called a bug) in the code. When that defect is executed and the system behaves wrongly, it is a failure.
Testing types and levels
6. What are the levels of testing?
Unit testing (individual functions, usually by developers), integration testing (modules working together), system testing (the full application) and user acceptance testing (business users confirm it meets their needs).
7. Smoke vs sanity testing?
| Smoke testing | Sanity testing |
|---|---|
| Checks a new build is stable enough to test | Checks a specific fix or change works |
| Broad and shallow | Narrow and deep |
| Done on every new build | Done after minor changes or bug fixes |
8. Retesting vs regression testing?
Retesting confirms that a specific bug is fixed by running the failed test again. Regression testing checks that the fix or a new feature did not break anything that worked before.
9. Functional vs non-functional testing?
Functional testing checks what the system does, such as login or checkout. Non-functional testing checks how well it does it: performance, security, usability and compatibility.
10. Black box, white box and grey box testing?
Black box testing uses only inputs and outputs with no code knowledge. White box testing uses knowledge of the code, such as covering every branch. Grey box testing mixes both, for example checking the database after a UI action.
11. What is exploratory testing?
Learning, designing and executing tests at the same time, guided by experience and curiosity rather than scripts. It finds bugs that scripted tests miss, especially in new features.
Test design techniques
12. What is boundary value analysis?
Testing at the edges of valid ranges, where bugs are most common. If an age field accepts 18 to 60, test 17, 18, 19, 59, 60 and 61.
13. What is equivalence partitioning?
Dividing inputs into groups that should behave the same and testing one value from each. For the age field: below 18 (invalid), 18 to 60 (valid) and above 60 (invalid).
14. What is a decision table?
A table of conditions and expected actions that makes sure every combination is tested. It is useful for rules such as discounts that depend on membership and order value.
15. Write test cases for a login page.
| ID | Scenario | Expected result |
|---|---|---|
| TC01 | Valid email and password | User reaches the dashboard |
| TC02 | Valid email, wrong password | Error message, user stays on login |
| TC03 | Empty fields | Required field messages shown |
| TC04 | Five wrong attempts | Account locked or captcha shown |
| TC05 | Password field | Characters are masked |
| TC06 | Forgot password link | Reset page opens |
| TC07 | SQL text such as ‘ OR 1=1 in email | Login rejected safely |
16. Test case vs test scenario?
A scenario is a high-level idea of what to test, such as verify login. A test case is the detailed version with preconditions, steps, test data and expected result.
Defects and bug reports
17. What goes into a good bug report?
A clear title, environment (browser, device, build), steps to reproduce, expected result, actual result, severity, priority, and evidence such as screenshots, videos or logs.
18. Severity vs priority?
Severity is how badly the bug affects the system. Priority is how soon it must be fixed. A spelling mistake in the company name on the home page is low severity but high priority. A crash in a rarely used admin report can be high severity but lower priority.
19. Explain the defect life cycle.
New, assigned, open, fixed, retest, then verified and closed. Along the way a bug can be rejected, deferred, marked duplicate or reopened if the fix does not work.
20. A developer says it is not a bug. What do you do?
Check the requirement again, reproduce the issue with clear evidence, and discuss it calmly with the developer. If you still disagree, involve the business analyst or product owner to decide.
Agile and tools
21. What does a tester do in a Scrum team?
Joins sprint planning and backlog refinement to clarify acceptance criteria, writes tests while features are being built, tests stories within the sprint, and joins the daily stand-up and retrospective.
22. What is the Definition of Done?
An agreed checklist a story must meet to be complete, such as code reviewed, tests passed, no open critical bugs and documentation updated.
23. Which tools have you used?
Common answers are Jira for bugs and stories, TestRail or Zephyr for test cases, Postman for API testing, browser DevTools, and SQL clients for database checks. Mention only tools you have actually used.
24. How do you test an API with Postman?
Send requests with different methods and data, check status codes, response body, headers and response time, and add simple test scripts. Test negative cases such as missing fields and invalid tokens.
25. Why should testers know SQL?
To verify that data was saved correctly after a UI action, prepare test data, and investigate bugs. Know SELECT, WHERE, JOIN, GROUP BY and basic UPDATE.
Scenario questions
26. How would you test a pen?
Interviewers want structure, not a long list. Group your ideas: functional (does it write, does the cap fit), usability (grip, weight), durability (drop test, ink life), compatibility (different papers) and safety (non-toxic ink).
27. How do you decide when to stop testing?
When exit criteria are met: planned tests are executed, critical and high bugs are fixed, coverage targets are reached, and the remaining risk is accepted by stakeholders. Deadlines also play a part, so communicate risk clearly.
28. You have one day to test a release. What do you do?
Run a smoke test, then focus on high-risk and most-used features, new changes and areas with past bugs. Share what was not tested so the team can make an informed decision.
29. How do you test a feature with no requirements?
Talk to the developer and product owner, look at similar features and competitor products, use exploratory testing, and write down your assumptions so they can be confirmed.
30. Why do you want to be a tester?
Give a genuine reason, such as enjoying finding problems before customers do, and show it with an example of a bug you found while practising on a demo site.
Frequently asked questions
Is manual testing still a good career?
Yes as a starting point, but grow into automation within a year or two. Testers who know manual testing well and can also automate with Selenium, Playwright or API tools are in strong demand.
Do I need an ISTQB certificate?
It is not required, but ISTQB Foundation helps freshers get shortlisted because it shows you know the standard terms used in interviews.
Where can I practise testing?
Use public demo sites built for practice, test open-source apps, and file well-written bug reports in a portfolio document you can show in interviews.
Browse more software testing tutorials, or prepare for SQL checks with our SQL interview questions.
