Blackbox testing Interview Questions and Answers in 2025 (100+ Q&A)

Blackbox testing Software Quality Assurance Engineer

Ques:- What is white box testing and what is black box testing

Asked In :- testhouse,

Right Answer:
White box testing is a testing method where the tester has knowledge of the internal workings of the application, allowing them to test specific code paths and logic. Black box testing, on the other hand, is a testing method where the tester evaluates the functionality of the application without any knowledge of its internal code or structure, focusing solely on input and output.

Blackbox testing Software Quality Assurance Engineer

Ques:- Testing scenario on “Malfunctioning of LIFT”

Asked In :-

Right Answer:
1. Verify that the lift does not respond to button presses.
2. Check if the lift doors fail to open or close properly.
3. Test for unusual noises or vibrations during operation.
4. Ensure the lift does not stop at selected floors.
5. Validate emergency features, such as alarms and communication systems.
6. Assess the lift's behavior during power outages or fluctuations.
7. Confirm that safety mechanisms, like overload sensors, are functioning.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- When would you choose bottom up methodology?

Asked In :- VECV, Kochar Infotech, vas, testhouse, textnow,

Right Answer:
You would choose the bottom-up methodology when you want to test individual components or modules first before integrating them into the overall system, especially when those components are well-defined and can be tested independently. This approach is useful when the components are complex and need thorough validation before integration.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is difference between BVA and Equivalence Partitioning ?can u explain BVA for three digits?

Asked In :- Intelligraphics, BCOM Computer Centre, mindpearl, newscred, housecall pro, clarasys, forter, planit software testing,

Right Answer:
Boundary Value Analysis (BVA) and Equivalence Partitioning are both testing techniques used in black-box testing.

**Difference:**
- **Equivalence Partitioning** divides input data into valid and invalid partitions to reduce the number of test cases. It assumes that all values in a partition will behave similarly.
- **Boundary Value Analysis** focuses on testing at the boundaries of these partitions, as errors often occur at the edges.

**BVA for three digits (0-999):**
- Valid boundaries: 0, 999
- Invalid boundaries: -1, 1000

Test cases would include:
1. Lower boundary: 0
2. Just above lower boundary: 1
3. Just below upper boundary: 998
4. Upper boundary: 999
5. Just above upper boundary: 1000
6. Just below lower boundary: -1

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Difference between Black box and White box testing?

Asked In :- Northrop Grumman, instashop - your grocery shopping app,

Right Answer:
Black box testing focuses on testing the functionality of the software without knowing its internal code structure, while white box testing involves testing the internal logic and structure of the code.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Design a black box test suite for a program that accepts two strings and checks if the first string is a substring of the second string and displays the number of times the first string occurs in the second string.

Asked In :- CIRRUS LOGIC INC, iks health, intact software, bis, quantstamp, inc., Cognitonic Systems Pty,

Right Answer:
Test Suite for Substring Occurrence:

1. **Test Case 1: Basic Match**
- Input: `("test", "this is a test test")`
- Expected Output: `2`

2. **Test Case 2: No Occurrence**
- Input: `("hello", "this is a test")`
- Expected Output: `0`

3. **Test Case 3: Empty First String**
- Input: `("", "this is a test")`
- Expected Output: `0`

4. **Test Case 4: Empty Second String**
- Input: `("test", "")`
- Expected Output: `0`

5. **Test Case 5: First String Longer than Second**
- Input: `("longstring", "short")`
- Expected Output: `0`

6. **Test Case 6: Case Sensitivity**
- Input: `("Test", "this is a

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Explian about boundary value analysis with an example ?

Asked In :- id tech camps, adaptavist, cloudendure,

Right Answer:
Boundary Value Analysis (BVA) is a testing technique that focuses on testing the boundaries between partitions. It involves selecting test cases at the edges of input ranges, as errors often occur at these boundaries.

For example, if a function accepts input values from 1 to 100, the boundary values to test would be:
- Just below the lower boundary: 0
- At the lower boundary: 1
- Just above the lower boundary: 2
- At the upper boundary: 100
- Just below the upper boundary: 99
- Just above the upper boundary: 101

This ensures that the function behaves correctly at the limits of its input range.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Expain Equivalence Class Partion with an Example?

Asked In :- Trans Cosmos, tandem diabetes care, accenture philippines, anand engineering products pvt ltd,

Right Answer:
Equivalence Class Partitioning is a testing technique that divides input data into valid and invalid classes to reduce the number of test cases. Each class represents a set of inputs that should be treated the same by the system.

**Example:**

For a function that accepts age as input (valid range: 18-60):

- Valid Equivalence Classes:
- Class 1: Ages 18-60 (e.g., 18, 30, 45, 60)

- Invalid Equivalence Classes:
- Class 2: Ages < 18 (e.g., 17, 0, -5)
- Class 3: Ages > 60 (e.g., 61, 100)

You would test one representative from each class instead of testing every possible age.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is difference between boundary value analysis and Equivalnce partioning?

Asked In :- Pod Point, nendrasys,

Right Answer:
Boundary Value Analysis focuses on testing the boundaries between partitions, specifically the values at the edges (just below, at, and just above the limits). Equivalence Partitioning divides input data into valid and invalid partitions to reduce the number of test cases by testing one representative value from each partition.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Give examples of boundary value and equivalence partitioning test cases.

Asked In :- Manipal Technologies, Freestone Infotech, Qualitrix, Itlize Global, spi global,

Right Answer:
**Boundary Value Test Cases:**
1. For an input field that accepts values from 1 to 10:
- Test case 1: Input 1 (lower boundary)
- Test case 2: Input 10 (upper boundary)
- Test case 3: Input 0 (just below lower boundary)
- Test case 4: Input 11 (just above upper boundary)

**Equivalence Partitioning Test Cases:**
1. For an input field that accepts values from 1 to 10:
- Valid partition: Input 5 (within range)
- Invalid partition: Input -3 (below range)
- Invalid partition: Input 15 (above range)

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is equivalence class partition?

Asked In :- torc robotics, behavox,

Right Answer:
Equivalence class partitioning is a testing technique that divides input data into valid and invalid classes, where each class represents a set of inputs that should be treated the same way by the system. This helps in reducing the number of test cases while ensuring coverage of all possible scenarios.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Black Box testing attempts to find errors in which of thefollwing categories1)Incorrect or missing functions2) Interface errors3)Performence errors?

Asked In :-

Right Answer:
All of the following categories: 1) Incorrect or missing functions, 2) Interface errors, 3) Performance errors.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- How to write test cases for boundary value analysis andequality partitioning?

Asked In :- realization technologies,

Right Answer:
To write test cases for boundary value analysis and equivalence partitioning:

1. **Boundary Value Analysis (BVA)**:
- Identify the boundaries of input ranges.
- Create test cases for values at, just below, and just above the boundaries.
- Example: For an input range of 1 to 10, test cases would be: 0, 1, 2, 9, 10, 11.

2. **Equivalence Partitioning (EP)**:
- Divide input data into valid and invalid partitions.
- Create test cases that represent each partition.
- Example: For an input range of 1 to 10:
- Valid partition: 5 (valid input)
- Invalid partitions: 0 (below range), 11 (above range), -1 (negative number).

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is the Technique followed to test Login Screen(Web)BVA or Equivalent Partition why?

Asked In :- LibSys, Finacle Technologies, Dynata, austrac,

Right Answer:
The technique followed to test a Login Screen (Web) is Equivalence Partitioning. This is because it allows us to identify valid and invalid input scenarios efficiently by grouping inputs that should produce similar results, reducing the number of test cases needed.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- Can any 1 tell me what is front-end testing & what isback-end testing with example ?

Asked In :- TVISHA TECHNOLOGIES PVT, western digital, crest infotech,

Right Answer:
Front-end testing focuses on the user interface and user experience of an application. It checks how the application looks and behaves from the user's perspective. For example, testing a website's buttons, forms, and navigation to ensure they function correctly.

Back-end testing, on the other hand, involves testing the server-side components, databases, and application logic. It ensures that the data processing, storage, and retrieval are working correctly. For example, verifying that a database returns the correct data when a query is executed.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is the main purpose of having Equivalence Class Particition & Boundary value analysis in Testing?

Asked In :- Goodera Information Technologies, sandf technologies,

Right Answer:
The main purpose of Equivalence Class Partitioning is to reduce the number of test cases by grouping inputs that are expected to produce similar results, while Boundary Value Analysis focuses on testing the edges of these input ranges to identify potential errors at the boundaries. Together, they help ensure comprehensive test coverage and improve testing efficiency.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is black box testing, and what are the methods for BBTplz explain it

Asked In :- UCA, Oremus,

Right Answer:
Black box testing is a software testing method where the tester evaluates the functionality of an application without looking at its internal code structure. The tester focuses on inputs and expected outputs, ensuring the software behaves as intended.

Methods for black box testing include:

1. **Equivalence Partitioning**: Dividing input data into valid and invalid partitions to reduce the number of test cases.
2. **Boundary Value Analysis**: Testing at the boundaries between partitions to identify edge cases.
3. **Decision Table Testing**: Using a table to represent combinations of inputs and their corresponding outputs.
4. **State Transition Testing**: Testing the application based on its state changes in response to different inputs.
5. **Use Case Testing**: Validating the application based on user scenarios and requirements.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is Equivalence Partitioning and Boundary Value Analysis. Is Boundary Value is subset of Equivalence Partitioning??

Asked In :- Testronic Labs, wso2,

Right Answer:
Equivalence Partitioning is a testing technique that divides input data into valid and invalid partitions to reduce the number of test cases while ensuring coverage. Boundary Value Analysis is a technique that focuses on testing at the boundaries of these partitions, as errors often occur at the edges. Yes, Boundary Value Analysis is considered a subset of Equivalence Partitioning.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- How to write integration test cases? And as a black box tester do we write integrated test cases and how?

Asked In :- Webvillee Technology, nrsp inc.,

Right Answer:
To write integration test cases, follow these steps:

1. **Identify Integration Points**: Determine the modules or components that interact with each other.
2. **Define Test Scenarios**: Create scenarios that cover the interactions between integrated components, focusing on data flow and communication.
3. **Specify Input and Expected Output**: Clearly outline the input data for each scenario and the expected results after integration.
4. **Prepare Test Environment**: Set up the necessary environment that mimics the production setup for accurate testing.
5. **Execute Tests**: Run the test cases and observe the behavior of the integrated components.
6. **Document Results**: Record the outcomes, noting any discrepancies between expected and actual results.

As a black box tester, you do write integration test cases by focusing on the inputs and outputs of the integrated components without needing to understand their internal workings.

Blackbox testing Software Testing Engineer/ Test Automation Engineer

Ques:- What is equivalence partition? what is the use of it?

Asked In :- Waffor, Meril Life Sciences, Infoane, EffiaSoft, ntp, vymo,

Right Answer:
Equivalence partitioning is a testing technique that divides input data into valid and invalid partitions or groups. The idea is that if one test case from a partition passes, all other cases in that partition are likely to pass as well, and vice versa. This helps reduce the number of test cases while still ensuring comprehensive coverage of the input space.

Welcome to the Blackbox Testing category on takluu.com, specially curated for software testers and QA professionals preparing for interviews and real-world testing challenges.

Blackbox Testing is a vital software testing technique where the tester evaluates the functionality of an application without peering into its internal code structure. This approach focuses on testing software against its requirements and specifications to ensure the final product meets user expectations.

This category covers essential topics such as:

Fundamentals of Blackbox Testing methodology
Types of Blackbox Testing: functional, non-functional, regression, and acceptance testing
Test case design techniques: equivalence partitioning, boundary value analysis, decision tables
Defect lifecycle and bug reporting
Differences between Blackbox and Whitebox testing
Tools and best practices for Blackbox Testing

Common interview questions include:

What is Blackbox Testing and how does it differ from Whitebox Testing?
Explain boundary value analysis with an example.
How do you design effective test cases for Blackbox Testing?
What types of defects can Blackbox Testing catch?
Describe the defect lifecycle in software testing.

Whether you’re an aspiring QA Engineer, Test Analyst, or Software Tester, understanding Blackbox Testing thoroughly will improve your testing strategy and interview performance.

At takluu.com, we provide detailed explanations, real-life examples, and updated questions to help you gain confidence and crack your testing interviews.

Start learning Blackbox Testing concepts now and boost your software testing career with takluu.com.

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