Complete Manual Testing Interview Questions & Answers (2026)

Answer: Software testing is the process of evaluating and verifying that a software application works as expected. It involves executing a system to identify bugs, gaps, or missing requirements.

Example: Checking if a banking app correctly transfers money between accounts while maintaining security and data integrity.

Answer: The seven principles defined by ISTQB are:

1. Testing shows presence of defects — Testing can prove defects exist but cannot prove they don't.
2. Exhaustive testing is impossible — You cannot test everything; use risk-based prioritization.
3. Early testing saves time & money — Shift-left testing reduces costs.
4. Defects cluster together — Most bugs are found in a small number of modules (Pareto 80/20 rule).
5. Pesticide paradox — Repeating the same tests finds no new bugs; review and update regularly.
6. Testing is context-dependent — E-commerce testing differs from healthcare app testing.
7. Absence-of-errors fallacy — A bug-free app that doesn't meet user needs is useless.

Answer: SDLC (Software Development Life Cycle) includes: Requirement Gathering → Analysis → Design → Development → Testing → Deployment → Maintenance.

Answer: STLC (Software Testing Life Cycle) includes: Requirement Analysis → Test Planning → Test Case Development → Environment Setup → Test Execution → Bug Reporting → Test Closure.

Practice these concepts with our AI Mock Interview.

Answer: A test case is a set of conditions used to verify a specific functionality.

Essential components:

• Test Case ID
• Test Title / Description
• Preconditions
• Test Steps
• Test Data
• Expected Result
• Actual Result
• Status (Pass/Fail)

Answer: BVA tests values at the edges of equivalence partitions.

Example: For a field accepting values 1–100: test 0 (invalid lower), 1 (valid lower), 2 (just above), 99 (just below upper), 100 (valid upper), 101 (invalid upper).

Answer: EP divides input data into valid and invalid partitions. Testing one value from each partition is sufficient.

Example: For an age field 18–60: valid partition 18–60 (test 30); invalid <18 (test 15); invalid >60 (test 65).

Answer: Decision tables capture business logic with combinations of conditions and their corresponding actions. Example: Login page: Username (Valid/Invalid) × Password (Valid/Invalid) × Captcha (Correct/Wrong) → 8 test combinations.

Answer: State transition testing verifies system behavior as it moves through different states. Example: ATM workflow: Idle → Card Inserted → PIN Entered → Menu → Transaction → Eject Card → Idle.

Answer: Regression testing ensures new code changes don't break existing functionality. Learn how this works in practice in our Selenium interview questions guide.

Answer: Simultaneous learning, test design, and execution without predefined test cases. Testers explore the application freely to find unexpected bugs.

Answer: Informal testing without planning or documentation. Done randomly to find defects missed by structured testing.

Answer: Testing with random inputs and actions to see how the system behaves under unexpected conditions. No test cases, no expected results.

• White Box: Tests internal code structure (unit testing, code coverage).
• Black Box: Tests functionality without knowing internal code (UI testing, API testing).
• Gray Box: Combination — knows partial internal structure (integration testing).

Answer: New → Assigned → Open → Fixed → Retest → Closed | Reopened → Deferred → Rejected.

• Clear and descriptive title
• Steps to reproduce
• Actual vs expected result
• Screenshots / video (if applicable)
• Environment details (OS, browser, device)
• Severity & Priority
• Test data used

Answer: When bugs are missed during testing and found by end users in production.

Answer: Number of defects per size of the software module (e.g., defects per KLOC).

Answer: Testing integrated throughout development in short iterations (sprints), with continuous feedback and collaboration.

Answer: In Agile, testing is planned per sprint rather than upfront. Test plans are lightweight and evolve continuously.

Answer: Share testing progress, blockers, and risks. Highlight bug trends and quality metrics.

Answer: Criteria a user story must meet to be considered complete — including testing, code review, documentation, and acceptance criteria.

Answer: Moving testing earlier in the SDLC. Testers participate in requirement analysis and design reviews before development begins.

Answer: Write failing tests first, then write code to pass them. Ensures code is testable and covers requirements.

Answer: Extension of TDD using natural language (Gherkin format: Given–When–Then) to define behaviors. Tools: Cucumber, SpecFlow.

Answer: A document mapping requirements to test cases, ensuring every requirement has a corresponding test.

Answer: A measure of how much of the application has been tested — includes requirements coverage, code coverage, and risk coverage.

Answer: A document prepared at test closure summarizing: what was tested, results, defects found, metrics, and recommendations.

Answer: Prioritizing testing based on the risk (probability × impact) of failure.

• Critical business functionality
• High-risk / high-impact areas
• Frequently used features
• Recently changed code
• Customer-reported issues

1. Testing without understanding requirements
2. Skipping negative test scenarios
3. Not updating test cases
4. Poor bug report quality
5. Ignoring exploratory testing

1. Positive: Valid username + password → success.
2. Negative: Invalid username, wrong password, empty fields.
3. Boundary: Max/min password length.
4. Security: SQL injection, brute force, session timeout.
5. UX: Remember me, forgot password, password visibility toggle.
6. Cross-browser: Chrome, Firefox, Safari, Edge.

1. Add items to cart → update quantity → remove items.
2. Apply coupon → verify discount.
3. Enter shipping address → validate fields.
4. Select payment method → complete payment.
5. Verify order confirmation email.
6. Edge cases: empty cart, expired coupon, payment failure, network timeout.

• File type validation (PDF, JPG, PNG)
• File size limits (test boundaries)
• Multiple file upload
• Special characters in filenames
• Upload progress indicator
• Cancel upload mid-way
• Network interruption during upload

You can extend any of these scenarios into automation later — see our Playwright interview questions and API testing interview questions for the next step.

1. Re-review the bug to confirm it's valid.
2. Provide clear evidence (steps, screenshots, logs).
3. Explain the business impact.
4. Escalate with the product manager if needed.
5. Document the discussion for future reference.

1. Ask clarifying questions to stakeholders.
2. Document assumptions.
3. Use exploratory testing to discover behavior.
4. Update test cases as requirements evolve.
5. Collaborate in refinement sessions.