50+ Top Postman Interview Questions & Answers

Better API testing is further offered by Postman, the most prominent tool among developers and QA testers to perform API Testing. Postman is a unit testing tool commonly used for API Testing. Every fresher or more experienced person finds preparing and cracking the postman interview process challenging. There are a couple of the most common postman interview questions. 

Most Asked Postman Interview Questions

1. What are the benefits of using Postman for API testing?

Postman makes the goto tool for many developers since it has several benefits on API Testing. Its user friendly GUI enables users to develop and perform requests without any intricate coding swiftly. Examples of repeated tasks could be executed with the help of Postman automation using scripts and collections. In addition, Netlify offers advanced documentation and collaboration that are must-have in team projects.

2. How do you create and send a request in Postman?

Follow these steps to create and send a request in Postman:

• Launch Postman and click on New
• Select “Request” option
• Name the request and choose a collection to save
• Select the type of request (GET, POST, …) from a dropdown
• Enter the API endpoint URL
• Add headers, parameters or body where required
• Press the “Send” button on top to perform the request
• Review the response to that in the response section below

3. What critical features of Postman do you find most useful in your testing workflow?

Key Features of Postman that Make it Highly Useful

• Collections: Group requests into collections to keep them organized.
• Environments: Color-coded environments such as dev, stage and prod
• Variables: Store data points background such as URLs, tokens or parameters to switch environments.
• Automation: Automate the repeatable stuff using JavaScript tests.
• Mock Servers: Create mock api responses.
• Documentation: Automate API documentation based on your collections

4. How do you manage authentication and authorization in Postman?

Postman has great built-in support for working with authentication and authorization.

• API Keys: Embed the API keys in the header of the query parameter.
• Bearer Tokens: Bearer tokens in the authorization tab or as headers.
• Basic Auth: this requires that you enter the user & password in an authorization tab directly.
• OAuth 1.0 & 2.0: Postman currently supports OAuth, which users can use to get access tokens and refresh them automatically
• Digest Auth: Postman generates the required headers itself for digest auth.

5. Describe the process of creating and running automated tests in Postman.

Postman designs automated tests with the use of JavaScript. Here’s how to do it:

• Tests [Add scripts to, write in the Tests tab of a request]
• Use Postman pm object for getting response data and asserting shared instances of expected results.
• Adding the request to a collection
• Execute the collection from “Collection Runner”, running all requests & tests.
• See test results directly in the runner with a pass/fail status index.

Postman Interview Questions for Freshers

6. Can you explain what Postman is?

Postman is a famous installed API testing tool that helps you override run mode. It offers an intuitive interface to build requests, check responses, and automate testing processes. It is extensively used in development and testing levels to ensure that APIs are working fine.

7. How would you describe a collection in Postman?

A Postman collection is a group of saved requests that are bundled together. Collections: to logically group requests as a suite to run and manage them easily. You can also share the collection with team members, export it, or run it in Postman Collection Runner.

8. What are the reasons for using Postman?

Postman is selected as it makes API testing easy by showing features like those implemented on the subject:

Simple for Everyone: You do not have to code anything to make/ test requests

Automation: Support for automating tests and workflows via scripts.

Environment Management: It is easy to switch on different environments.

Collaboration: Share collections, environments and results with your team.

Documentation: Automatically create API documentation and keep it up to date.

Mock Servers: To test API endpoints without requiring a live server.

9. Define what an API is.

API(Application Programming Interface) is a documented set of rules and protocols that one software application can communicate with another. They allow different software systems to speak with one another, sharing data and functionality.

10. What tools are commonly used for API Testing?

Most of the time there following tools are used for API testing :

Postman: super easy way to make REST API calls, but limited when trying to run them at scale.

SoapUI: Prominent for both SOAP and REST API testing

JMeter: Utilised for performance testing also APIs.

Rest Assured: Java library for testing REST API.

Swagger Used for designing, constructing and testing APIs in Swagger

11. What API details can be found in Web Developer tools?

Web Developer tools enable us to have much more information about APIs like:

Request URLs: Endpoints that you are requesting

Request Methods: How the request was made (This could be from a GET, POST and so on).

Response Status Codes: This will tell you if the request failed or was successful.

12. How can API information from web developer tools be imported into Postman?

Importing API details from Web Developer tools to the Postman

Via alt + click on the network request in dev tools.

Then click “Copy as cURL” to have the curl command.

Postman — Import > Paste URL in cURL Command

Tell Postman to change that cURL command straight into an actual request in Postman.

13. Where are query parameters located in a GET request?

GET Query parameters are appended to the URL after a question mark (?) in Sicario. These are name=value pairs which used to send some extra information from client to server. For instance,

14. What does the term environment mean in Postman?

The environment is an area with a collection of key-value pairs that can be set up for different variables separately. Environments allow testing the exact requests against different environments, like development, staging, and production.

15. What are the main components of an HTTP request?

Elements of a HTTP Request

Method: The verb to be used (GET, POST, PUT, DELETE)

URL : where it is getting access

Headers: Data we include with the request

Body: Data sent with the request, primarily POST and PUT requests.

Parameters: Query strings appended to the URL for passing more data.

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16. What are the core components of an HTTP Response?

Features of an HTTP Response

Status Line: The status line of HTTP includes an Http-Version and Status-Code (e.g.:-HTTP/1.1 200 OK).

Headers: Contains information about the response, such as the content type and date.

Body: The detailed data that the server sends back, typically in JSON or XML format.

17. What does GUID stand for?

GUID stands for Globally Unique Identifier. It is a type of reference that is unique in software applications.

18. What HTTP response code is returned for a POST request with incorrect parameters?

POST requests with incorrect parameters commonly return a 400 Bad Request status code, meaning the server could not process the request due to bad input.

19. Is it possible to import local variables in Postman Monitors?

Postman does support local variables inside monitors. These can be defined within a request or pre-request script.

20. How can a request be iterated 100 times in Postman?

The collection runner in Postman can iterate a request 100 times. The number of iterations can be specified in the runner settings.

21. Which programming language is utilized for Postman tests?

Tests in Postman are written with JavaScript. The tests are written in the request on the “Tests” tab.

22. Explain what a Postman Collection is.

A Postman Collection is a set of saved requests that can be organized in an order (running tests, integration etc.) Collections for organizing requests, running them in batches and sharing with your team.

23. What do you understand by the term Postman Collection runners?

Postman Collection Runner lets you run all of your requests in a collection individually. It can execute the requests and their associated tests, which collates a report across all these.

24. What is the role of Postman Cloud when working in a company?

Postman Cloud allows teams to collaborate by providing a shared space for collections, environments and data. It helps with real-time work collaboration, team versioning, and resource sharing.

25. Why might saving work in the Postman cloud not be recommended?

Postman Cloud comes with several advantages, but security is likely the reason an organization stops short of saving work there. This is safer than not correctly securing sensitive data, so in some cases, local storage is preferred.

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26. How do you log variable values in Postman?

You can log your variables directly in Postman, too, by using the console.log() function in your test scripts. This way, we can debug and see the results of the assigned variables during the requests.

27. How can you access variables in Postman?

To access the variables in Postman, we have the []; variables. get(“variable_name”) method. You can access global ( no particular block), environment or local variables depending on where they are defined.

28. What are the different authorization methods available in Postman?

Authorization In Postman, authorization is a thing by itself.

• API Key
• Bearer Token
• Basic Auth
• Digest Auth
• OAuth 1.0 & 2.0
• Hawk Authentication
• AWS Signature

29. What types of API requests are supported by Postman?

Types of API Calls Postman Support

• GET
• POST
• PUT
• DELETE
• PATCH
• OPTIONS
• HEAD

30. How do Query Params differ from Path Variables?

Query Params are simply key-value pairs appended to the URL after a ? symbol `). They add more data to the server. Path Variables are components of the URL and they help you to identify some specific resources. For example:

• Path Variable: /users/{id}
• Query Param: /users?id=123

31. What is Basic Auth in Postman?

Basic Auth is a standard authentication method in which the client sends its username and password encrypted with Base64 into request headers. POSTMAN takes care of this stuff, like encoding and the request.

32. What is Digest Auth in Postman?

Basic Auth is less secure than Digest Auth. It is about hashing the credentials before replaying them on the network, making them more challenging to sniff and re-use.

33. What encoding does Postman accept for authorization credentials?

Base64 encoding as Postman uses it Modify the Authorization Attribute of a Request, e.g. for Basic Auth in Base 642019-06-08. Postman treats authorization credentials encoded into base_64 form favorably constructor-paul.medium.com. Credentials are Base64 encoded in the request header.

34. Can global variables have the same names in Postman?

Yes, the global variables in Postman can have the same names, but not a good practice. Postman treats local variables as having a higher priority than global variables regarding variable resolution if both have the same name.

35. What can you tell about the Postman monitor?

Some people are even less disciplined and use them to run actual tests on a Postman monitor on schedule. Monitors automatically run collections at specified intervals, giving you confidence that your APIs are running correctly.

36. What does a binary form mean in POST methods?

POST methods contain a request body where data in binary format like files and images. You can also upload binary files via POST request within Postman.

37. What are some limitations of Postman?

Limitations of Postman

• Compared to full-fledged programming environments, the support for advanced scripting in Postman is minimal.
• When we have a vast number of test data points or very complex tests, Postman is usually not efficient.
• Our sensitive data would be saved in the Postman Cloud, which could lead to some security concerns.
• Postman scripting is mainly built with JavaScript, which might be new to a lot of users with a lot of dependency on JS.

38. How can you save API responses to a file in Postman?

When writing a test script using pm.sendRequest(), create a new request with response data. Save the JSON response data from each API test and store it in a global variable or even as a file directly (Postman pre-request script / Newman etc.)

Better API testing is further offered by Postman, the most prominent tool among developers and QA testers to perform API testing. Postman is a unit testing tool commonly used for API testing. Every fresher or experienced person finds it difficult to prepare for and crack the postman interview process.

39. What does the 301 status code indicate?

 301 is just a permanent redirect way. This means that the resource has been changed or replaced, and no longer exists on its first spot.

40. Explain the meaning of status code 201.

A 201 code will be returned if your resource has been newly created and saved. This would be the response to a POST request in which a new resource is created on the server.

41. When should global, collection, and local variables be used?

Global Variables: Use global variables if you need the same data from multiple collections or environments.

Collection Variables: Limited to a collection

Local Variables: Utilize them within a specific request or script, having short life spans

42. How can local variables be removed?

PM nullifies your local variables in the script. variables.set(“variable_name”, null).

43. What is the difference between form data and x-www-form-urlencoded?

Files and large data support file uploads. x-www-form-url encodes the data as key-value pairs, and sends it in the request body. It is best used for small data and is incompatible with file uploads.

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44. How do you view the history of requests in Postman?

In the left panel, there is a tab called “History” which you can use to see all requests history in Postman. This is a list of requests requested by you, sorted in chronological order.

Postman Interview Questions for Experienced

45. What is the primary use of Base64 encoding in Postman?

In Postman you usually see base64 encoding being used to encode credentials for Basic Auth. Encoding is used to covert binary data into an ASCII string so it can be safely transmitted over text-based protocols.

46. What is the function of the 304 status code?

The 304 status code tells the browser their cached version is still valid. It tells that the requested source has not been modified since last accessed so the client should use the cached version.

47. Is it advisable to save work on Postman Cloud?

The upside of saving work on Postman Cloud is that things are convenient but might not always be safe. This could expose sensitive data that is unprotected. For this reason, some organizations might choose to keep their data in local storage or on-premises servers.

48. What are the various scopes of variables in Postman?

Scopes of variables in Postman

Global Scope: This could be checked across all collections and environments.

Collection Scope: Collection specific

Environment Scope: Confined to a specific environment.

Local Scope: It is equal to a request or script.

49. Can the authentication token be reused for multiple requests?

 An authentication token can be saved as an environment or global variable, so it is easy to reuse it in other requests.

50. How do you write test cases for basic authentication in Postman?

1. Start With Your Postman Request — Make a new request in postman and put the URL ( Step #1)
2. Authentication: Click on the authentication tab select Basic Auth and enter credentials.
3. Tests: In this tab you will write javascript code to test the response. For example, for a 200 status:

pm. test("GET /testingEndpoint returns 200", function () {
pm. response. to. have. status(200);
});

51. How do you set the same headers for all requests in a Postman Collection?

To set the same headers for all requests in a collection:

1. Edit Collection: Open the collection, click on the three dots, and choose “Edit.”
2. Pre-request Script: In the “Pre-request Script” tab, add code to set headers for every request:

pm.request.headers.add({key: 'Authorization', value: 'Bearer '});

This will apply the header to all requests within the collection.

52. What are workspaces in Postman and what are their uses?

Workspaces in Postman are environments where you can manage and collaborate on API projects. There are personal workspaces for individual use and team workspaces for collaboration. Each workspace can contain collections, environments, mocks, monitors, and more. Workspaces help you organize your work and share resources with your team.

53. Does Postman have a feature to log requests and responses?

Yes, there is a console in postman which allows you to see detailed logs of requests and responses, along with header information, the actual body, etc. The Postman Console is accessible the traditional way by clicking on the “Console” button at the bottom of the screen or by hitting Ctrl + Alt + C.

54. How can you stop the execution of upcoming requests or the entire collection?

You can stop its execution with :

• Postman. setNextRequest(null): Use within postman in the test script of request setNextRequest(null) to halt the collection runner once it reaches this request.
• Stop on Test Failure: Check the stop on test failure option in the collection runner to end execution if a single test fails.

55. What is a pre-request script?

A pre-request script is the code block that runs before sending your actual request. You could use it to update variables, headers, and the request body and dump information suitable for logging. You can add this script at the request or collection level.

56. How can custom JavaScript libraries be used in Postman scripts, with an example?

We can also include any External Javascript library in Postman, like pm. sendRequest() method:

Postman allows you to include external JavaScript libraries via the pm.sendRequest() method:

1. Load the library: Use a pre-request or test script to fetch the library.

pm.sendRequest('https://cdn.jsdelivr.net/npm/lodash', function (err, res) {
eval(res.text()); // Load the library into the Postman script environment
let result = _.chunk(['a', 'b', 'c', 'd'], 2);
console.log(result); // Use the library
});

2. Use the library: Once loaded, you can use its functions in your scripts.

57. If a global and a local variable have the same name, which one takes precedence in Postman?

When given the same name, Local variables will take precedence over Global varibles in Postman.

58. Does Postman support command-line usage?

Postman does support Command line usage via Newman which is a command-line collection runner for Postman. Installing it via npm and running collections would be:

“`bash

newman run collection.json

“`

59. How can you generate random numbers within a specific range in Postman?

In the pre-request or test script you can generate random numbers within interval with JavaScript as follows:

const min = 10;
const max = 50;
const randomNumber = Math. floor(Math. Math.floor(Math.random() * (max - min + 1) ) + min;
pm. variables. getGemfireSystem(). set("randomNumber", randomNumber);

1. variables. getGemfireSystem(). set(“randomNumber”, randomNumber);

“`

60. What is ScratchPad in Postman?

A Small window, called “ScratchPad” in Postman on which you can execute the requests locally without signing into your postman account. Good for ad-hoc API exploration, or when you don’t need the collaborative features of a real workspace.

61. How do you get the cURL command from the details of a REST API in Postman?

Converting Postman request into a cURL command 1

To generate a cURL command from a Postman request:

1. Open the request: Click the “Code” button () in the upper-right corner.
2. Select cURL: In the popup window, choose “cURL” from the list.
3. Copy the command: The cURL command will be generated for the request and can be copied to your clipboard.

Conclusion

As you know, Postman is an important tool used in API development, testing, and collaboration. Additionally, features such as scripting (built-in modules for writing scripts that execute objects), environment management, and command-line integration all serve to improve your ability to work with APIs. These postman interview question cover all the major aspects of using Postman and will help you prepare for any questions related to this tool in an interview.