Top Postman Interview Questions and Answers

28. How to remove local variables?

Local variables are already temporary variables created during a request run.

They only exist for that particular request and cannot be manually deleted. You can clear or unset them if required. You can remove a local variable using:

29. Can we use authentication tokens for more than one request?

Authentication tokens can be reused for multiple API requests until they expire. Here are some of the common reasons behind their reusability:

• Tokens are issued to validate identity.

• Once issued, they remain valid for a certain duration.

• During that time, you don’t need to generate a new token for every request.

Example of using authentication tokens for multiple request:

30. Write a test case for basic authentication in Postman?

I am writing a test case to verify that the API accepts valid Basic Auth credentials and returns status 200. It involves the following steps:

• Set Authorization Type = Basic Auth

• Enter Username and Password

• Send request

• Add this script under Tests

Test Script:

Postman Interview Questions for Experienced Professionals

This section lists the most asked Postman interview questions for experienced professionals. These are often asked when you apply for a senior level job interview, like senior software developer or senior QA analyst.

31. What is the significance of using Base64 encoding in Postman?

Base64 encoding allows for the safe transmission and handling of binary data within text-based formats, such as JSON bodies, HTTP headers, and URLs. These are the primary means of communication for web APIs. You can use them for the following two applications:

• Sending Secret Login Codes (Passwords): The internet's standard way of sending your username and password to an API is to mash them together and then Base64 encodes them into a single, clean block of text. This is called Basic Authentication. The postman usually does this automatically for you!

• Sending Files (Like Images): The text-based internet (HTTP) can't safely carry the raw code of an image or a PDF. Base64 translates that image's binary code into a long string of letters and numbers that the internet can safely deliver without breaking the file.

32. Is it safe to save your work on Postman Cloud?

The platform does provide robust security measures to secure the user’s data. It is definitely safe to store data on its cloud. But there are loop holes too. As a user, you have the authority to manage the sensitive data within your account. This means the security of data completely depends on the security measures you are following. As long as you are following the best practices there is no danger.

33. How would you set the same headers for each request in a Postman Collection?

It is possible to set common headers at the collection level by editing the collection and adding headers under the ‘Headers’ tab. They will be applied to all requests automatically. Here are the steps to do it:

• Right-click on the Collection

• Select Edit

• Go to the Headers section

• Add your key-value header (e.g., Content-Type : application/json)

• Click Save

34. Can you stop execution of upcoming collections or requests? How?

It is possible to stop the execution of upcoming requests. All you have to do is to run one command inside the Tests tab. Here is how you do it:

• Open the request from where you want to stop execution

• Go to the Tests tab

• Add the following script:

• Now run the collection in the Collection Runner

35. Assuming you have two variables, a global and a local, both of them have the same name, which one will be preferred by Postman?

This platform will always prefer the local variable over the global variable as local variables have higher scope priority. This is not it, be it any variable the local variable will always be preferred. The reason behind this preference is the default priority list:

1. Local Variable

2. Data Variable

3. Environment Variable

4. Collection Variable

5. Global Variable

36. Can we use the command line in Postman?

Command line can not directly access the Postman. You can do it by using tools like Postman CLI (Command Line Interface) and Newman. These tools help you to run collections, integrate with CI/CD pipelines and automate tests outside of the main application. Here are the steps to use the Newman tool:

• Install Newman:

• Run a Collection from command line:

37. Assuming you have all the details of a REST API, how would you get the cURL command?

I will use the given steps:

To get the cURL command in Postman, I would:

1. Create the Request

• Enter the API URL, select the HTTP method (GET/POST/PUT/DELETE).

• Add headers, params, body, and auth as required.

2. Open the Code Snippet Option

• Click on the </> Code button (usually on the right side of the request builder).

3. Select cURL

• In the popup, choose cURL from the list of languages.

4. Copy the Command

• Postman will generate the full cURL command.

• Click Copy and use it in the terminal.

38. Suppose you have a range given. How would you generate random numbers from this range?

It is an easy process. You just have to use the right formula using JavaScript. The formula is:

Example: (Range 10 to 50)

39. How to access the history of requests in Postman?

You can see or access the request history from the History tab available on the left panel. Here are the steps to do it:

1. Open Postman

2. Go to the Left Sidebar

3. Click on History

4. You will see all the previously executed requests listed with:

• URL

• Method

• Timestamp

40. Do you find any limitations in Postman? List them.

I have used different Postman alternatives for some specific tasks. So, I can say there are some limitations or areas where this platform lacks. Some common limitations are:

1. Cannot perform UI or functional web testing, only API testing.

2. Limited support for complex API workflows without scripting.

3. Does not store variable updates permanently during Monitor runs.

4. Can run collections from CLI only through Newman, not directly.

5. Limited performance/load testing capability.

6. Collaboration features require paid plans.

7. JSON formatting errors are not auto-corrected.

8. Supports testing HTTP APIs only, not SOAP or GraphQL extensively.

Read Also- What is Google AI Studio? A Complete Guide for Beginners

Postman API Testing Interview Questions

Now we will discuss some of the most asked Postman interview questions and answers based on real problems. These questions are generally asked to professionals with more than 3 years of experience.

41. How would you use Postman to validate a POST API /users that creates a user, Validate status code, JSON fields (name, job), and basic structure.

1. Set request method to POST and URL: https://reqres.in/api/users

2. In Headers, add: Content-Type: application/json

3. In Body → raw → JSON, add:

4. Go to the Tests tab and add:

Output / Result: Tests pass if status = 201, name and job match request, and id + createdAt exist.

42. Use Postman to automatically use a Bearer token stored in an environment variable for all secured requests.

1. Create an Environment → add variable: token =

2. In your request, go to Authorization tab:

• Type: Bearer Token

• Token: {{token}}

3. Alternatively, set header manually in Headers: Authorization: Bearer {{token}}

4. In Tests, validate that unauthorized responses are not received:

Output / Result: Request is sent with Bearer token from environment; test fails if API returns 401/403.

43. Write Postman tests to ensure a GET /users/2 API still returns required fields (id, email, first_name, last_name).

Steps:

1. GET Method - URL: https://reqres.in/api/users/2

2. In Tests, add:

Output / Result: If the backend removes or renames any of these fields, Postman tests will fail, flagging breaking changes.

44. Use Postman to verify that a GET API responds within 500 ms.

Steps:

1. Method - URL example: https://jsonplaceholder.typicode.com/posts

2. In Tests, add:

3. Run the request multiple times or via Collection Runner.

Output / Result: Test passes only if responseTime < 500. This is commonly used for performance SLAs.

45. Simulate a login flow: first call /login to get a token, then use it in /users API.

Steps:

1. Request 1: Login

• Method: POST

• URL: https://reqres.in/api/login

• Body (JSON):

2. Request 2: Get Users

• Method: GET

• URL: https://reqres.in/api/users?page=2

• Headers: Authorization: Bearer {{authToken}}

• Tests:

Output / Result: Token from login is stored in authToken and used automatically in the second request. Both tests pass if token and auth are correct.

46. Ensure an API returns 400 Bad Requests when required fields are missing.

Steps:

1. POST Method - URL: https://reqres.in/api/register

2. Body (JSON) – intentionally incomplete:

3. Tests:

Output / Result: Verifies that the backend correctly validates input and returns error with a message.

47. Use Postman Collection Runner to send multiple POST /users requests with different user data from a CSV.

Steps:

1. Create a request:

• Method: POST

• URL: https://reqres.in/api/users

• Body (raw JSON):

2. Prepare users.csv:

name,job

Alice,Engineer

Bob,Manager

Charlie,Designer

3. Open Collection Runner → select the collection → choose file users.csv.

4. In Tests:

Output / Result: Each CSV row becomes a separate run. Tests assert that API echoes the correct name and job per row.

48. Use Postman to confirm that a public API returns proper rate limit headers (e.g., X-RateLimit-Limit, X-RateLimit-Remaining).

Steps:

1. GET Method - Example URL: https://api.github.com/users/octocat

2. In Headers, add: User-Agent: Postman

3. In Tests:

Output / Result: Confirms the presence of rate limiting info, which is a very common real-world need.

49. Create and test a Postman Mock Server for /products when backend is not yet implemented.

Steps (high-level):

1. In Postman, create a new collection with a GET /products request.

2. In the example response for that request, define:

3. Right-click the collection → Mock Collection → choose environment (or none) → create.

4. You’ll get a mock URL like: https://.mock.pstmn.io/products

5. Send a GET request to this mock URL and add Tests:

Output / Result: You can integrate this mock endpoint with the frontend until the real backend exists.

50. Use Postman tests to log response details and help debug 5xx server errors.

Steps:

1. Use any endpoint that may return errors (e.g., a staging URL).

2. In Tests:

Output / Result: If a 5xx happens, detailed logs appear in Postman Console, and the test fails, highlighting server-side issues.

Wrapping Up Postman Interview Questions

We have discussed various Postman interview questions and answers for different experience levels throughout this article. By exploring them you will be completely ready to crack any type of interview. Just remember the key: Answer each question with confidence and clarity. Then you will easily get the job of your dreams.

FAQs

Q1. Is Postman a CI/CD tool?

It is not a CI/CD tool itself. It integrates with other CI/CD tools like jenkins for API testing in the pipeline. This allows a continuous quality check on different code changes.

Q2. What is the salary of a Postman professional?

The average salary of these professionals is 20.7 LPA in India and $46k - $85k per annum in the USA.

Q3. Does Postman provide a free account?

This platform does provide a free subscription account to individuals and teams of less than 3 people. It comes with limitations of features and runs (25 runs/month).

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