What is Happening When You Could Not Send a Request on Postman

The "Could not send request" error in Postman can impede your API testing workflow. This guide will delve into effective troubleshooting techniques to pinpoint the root causes of the problem!

Steven Ang Cheong Seng

Steven Ang Cheong Seng

27 July 2025

What is Happening When You Could Not Send a Request on Postman

For developers and testers, encountering the "Could Not Send Request" error in Postman can be a frustrating roadblock. This error message, while seemingly straightforward, can arise from a variety of underlying issues.  This article dives deep into the potential causes of this error, from network connectivity problems to configuration mistakes within your request. We'll equip you with the knowledge to diagnose the issue effectively and get your requests flowing smoothly again.

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Apidog is a free API development platform that provides developers with complete functionalities for the entire API lifecycle. Whether you are new or experienced in creating APIs and applications, Apidog's intuitive user interface allows developers to easily adapt to the new working environment.

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Apidog An integrated platform for API design, debugging, development, mock, and testing
REAL API Design-first Development Platform. Design. Debug. Test. Document. Mock. Build APIs Faster & Together.
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Postman - Software Application for All Things API

Postman is similar to a one-stop solution for developers who wish to work with APIs. It can streamline the process of building, testing, and documenting APIs, and allow developers to create and send API requests.

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Key Features of Postman

Craft and Send Requests:

Unveiling the Response:

Organized Workflows:

Environments for Different Stages:

Robust Testing Capabilities:

Collaboration Made Simple:

Effortless Documentation:

Potential Reasons Why Requests Cannot be Sent on Postman

There are a lot of reasons why some Postman requests that you want to send cannot be done. This section below highlights a few of the common reasons.

Network Connectivity:

Proxy Server Issues:

Request Construction Errors:

Server-Side Issues:

Postman Bugs:

Additional Considerations:

These are just a few of the reasons why "Could not send request" messages may be received. To ensure that you understand more about the errors, check out the official Postman documentation regarding troubleshooting API requests.

Debug API requests using the Postman Console | Postman Learning Center
Postman is a collaboration platform for API development. Postman’s features simplify each step of building an API and streamline collaboration so you can create better APIs—faster.

Apidog - Gain Complete Transparency Over APIs

Apidog is a free-to-use API development tool that equips developers with every essential function for perfecting an API. With Apidog, you can create, test, document, and mock APIs within a single API. This means that you can depend solely on Apidog to deal with all your API development processes!

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Apidog An integrated platform for API design, debugging, development, mock, and testing
REAL API Design-first Development Platform. Design. Debug. Test. Document. Mock. Build APIs Faster & Together.
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Observing Actual (or Raw) Requests with Apidog

view actual response apidog

Once you have finished creating your API, you can see how your API will send the request by selecting the Actual Request header. This will ensure that you understand what and how your APIs will interact with the back-end side. You can then see the raw request, similar to Postman.

Guide: How to View Postman Raw Requests?
Master the Postman API tool by learning how to view raw requests! This article will guide you to view the exact data sent during API calls, allowing you to troubleshoot issues and dissect API interactions.

Testing API Using Apidog

After modifying your APIs, it is time to observe if it works without encountering any errors!

To target the correct API endpoint to access the API, you first have to insert the corresponding API endpoint that you want to test. Once you have included the intended API URL, include the parameters that you want to use for the endpoint (if relevant).

In case you are unfamiliar with passing multiple parameters in an API URL, check out this article to find out how you can specifically target a resource inside a rich collection of data!

Tutorial: How to Pass Multiple Parameters in REST API URLs?
Two commonly seen parameter types are widely used in modern websites. Although they slightly differ based on their functions, parameters help developers identify specific resources found within a collection or system.

Conclusion

The "Could not send request" error in Postman can be a frustrating hurdle, but with a methodical approach, you can identify and address the culprit. This guide has equipped you with the knowledge to troubleshoot common causes, from network connectivity issues to request configuration errors.

Remember, the API documentation is your friend – it often provides valuable insights into authentication requirements, request formats, and known server issues. By leveraging the troubleshooting techniques outlined here and consulting the documentation, you'll be well on your way to resolving the error and getting your Postman requests flowing smoothly again.


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