How to set Content-Type to application/json? The server requires the Content-Type to be application/json.

You can follow this tutorial to set Content-Type to application/json using the "HTTP Header Manager" Config Element.

1. Copy and create a Test Plan called Azure-Echo-API-JSON-3.jmx.

2.Add a "Config Element > HTTP Header Manager" to "Post a Valid JSON" sampler with the following header lines:

Name: Content-Type
Value: application/json

3. Run the test plan with a Debug PostProcessor and open the "View Results Tree" listener.

4. Inspect the request of the "Post a Valid JSON" sampler. You see the header line of "Content-Type: application/json".

5. Of course, you can add any other header lines as required by the server. Examples are: Authorization, Subscription-Key, Application-Key, etc.

The picture below shows you how to set Content-Type to application/json using the HTTP Header Manager:

⇒ JSON Extractor - Capture JSON Data

⇐ HTTP POST with JSON Message

⇑ Working With JSON Body Messages

⇑⇑ Apache JMeter Tutorials