How to Master Data-Driven Testing with Postman

Learn how to loop through a CSV file in Postman to automate your API tests and handle dynamic data! In this tutorial, we’ll explore:
✅ Using Postman Runner to iterate over CSV data
✅ Accessing data dynamically in query parameters
✅ Leveraging JavaScript to access data in pre-request and test scripts

You’ll learn step-by-step how to work with a sample CSV file containing:
- Region (US States)
- Search Count for 'Boba'

This tutorial will show you how to:
- Configure Postman variables with CSV data
- Use Postman Runner to process multiple iterations of API requests
- Dynamically reference data in query parameters using curly braces

📚 Chapters:
00:00 Introduction
00:21 Configure Postman variables with CSV data
01:24 Use Postman Runner to process multiple iterations of API requests
01:41 Dynamically reference data in query parameters
02:01 Use JavaScript to script with data programmatically

💡 Helpful Links and Resources:

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#Postman #CSVFile #DataAutomation #APITesting #PostmanRunner #APIAutomation #ProgrammingTutorial

[levels]

Thanks ma'am, this saved me from a whole lot of trying and failing to read through the data file👏🙌

[siddeshkumarb]

This automation saved lot of time. Thank you so much :)

[DavidCSaint]

These specific explanations are awesome. Thank you.

[vbond]

Thanks. What if I want to do load testing and test, say, a 100 users concurrently, instead of one by one? I have tried the Performance testing tab in Postman runner, but it repeats the same user virtually instead of picking up multiple users from a file (there doesn't seem to be any way to take input from a file in that performance test tab)

[azkymubarack]

helped me many times this video. thank you

[GRHood]

thank you, is that possible to use 'while' statement at postman. I need to call endpoint until I get my flag false, but postman crushing if I do that with 'while'

[Afrowa]

I tried to follow your steps, but my test was unsuccessful. I only have 6 items in my headers vs your 8. Is it possible to share the items under the header section?

[ViCNoob]

Can I also use variable inside the csv file?
I have scenario that I have a Create request, then I will set the newId variable after the the request runs
In the PUT request to edit, i have the url: "someUrl/{{newId}}". For normal case I dont need the data newId set in the csv file, but I want to test the abnormal case that newId = -1 (that should be set from the CSV file). Can I achieve it somehow?

[sebascouto]

I did not know how to get comma in csv to match correctly in postman. In my case, yes I require to create two environment variables to store its data during execution. Thanks for this valuable video.

[pavatjunsomboon]

i need to export respond body in runner function in json from

[joseardzm]

somehow is not working for me, only for POST I can use variables

[pragun]

Can I put the content of body to csv and use it in a runner? If yes, what do I put in the body of request? Variable/CSV Header name, just like how you showed for query params?

[ThePutra]

What if the data is picture? Like picture01, picture02, picture03, etc.

[nikhilviyatnampadi]

*How do we loop with data file while running on jenkins or CI?*

[danishafzal]

How to use when we have path parameter ?

[purnimaduggal]

How to combine the response body of each requests into a single response body

[exocast]

I can't upload the CSV on my mac. It will say "Couldn't upload file
Make sure that Postman can read files inside the working directory."
Within the settings, it is not allowing me to set up a different folder. Do you have any idea?

[RossZhu-gk]

Thanks for your tutorial which is very clear and helpful! There seems to be a drawback of Postman on bulk testing. What if I have multiple requests to test? It only allows a single Data File which must be applied to all the requests, which forces all the requests to run through the same number of iterations... This means if I have 100 test cases for request1, 5 test cases for request2, then I have to run 200 cases (95 tests for request2 will be bogus) instead of 105.

[iam_royy]

How can I capture the response that will get generated after 51 iterations?

[dharshichannel]

Will this work even if we pass csv file with 10000+ data rows?