How to Test Azure Functions Through Postman and Azure Portal ?

Azure Functions can be tested easily without writing any client application. Two of the most common methods are Postman (for HTTP-triggered functions) and the Azure Portal (for all triggers). This guide explains both methods step-by-step.

1. Testing Azure Functions Using Postman

Postman is the most convenient tool to test HTTP Trigger Azure Functions.

Prerequisites

• Function must be running locally (func start) or deployed to Azure.
• You need the Function URL with the function key.

Steps

Step 1: Get the Function URL

If running locally:

http://localhost:7071/api/<FunctionName>

If running in Azure:

• Open Azure Portal → Function App.
• Select your function → Get Function URL.
• Copy the URL (it includes code=<function_key>).

Step 2: Open Postman and Create a Request

• Select GET, POST, PUT, or DELETE depending on your function.
• Paste the function URL.

Step 3: Add Input Data

For GET:

• Add query parameters.

For POST/PUT:

• Go to Body → choose raw → JSON.
• Enter JSON input.

Example:

{
  "name": "ViASTUDY",
  "score": 90
}

Step 4: Send the Request

Click Send.

Postman will display:

• Response status (200, 400, 500, etc.)
• Response body
• Execution time
• Headers

Step 5: Check Logs (optional)

If running locally:

• Check the terminal running func start.

If in Azure:

• Check Monitor tab → Logs.

2. Testing Azure Functions Using Azure Portal

Azure Portal allows testing without any external tool.

Useful when:

• You don’t have Postman installed.
• You want quick tests after deployment.

a. Testing HTTP Trigger Functions

1. Go to Azure Portal → Function App → select your function.
2. Click Code + Test.
3. Select Test/Run tab.
4. Choose HTTP Method (GET/POST).
5. Add headers, query parameters, or body.
6. Click Run.

Results You Will See:

• Response body
• Status code
• Execution logs (right panel)
• Invocation details

b. Testing Timer Trigger Functions

Timer triggers cannot be run manually on schedule, but you can test them:

1. Go to the function in Azure Portal.
2. Click Code + Test.
3. Click Run.
4. The function will execute once immediately for testing.

c. Testing Queue/Blob Trigger Functions

These functions react to Azure Storage events.

Queue Trigger Test Steps:

1. Open Storage Account → Queues.
2. Select the queue linked to the function.
3. Add a new message with test JSON/text.
4. Save.
5. Azure Functions automatically picks the message.
6. Check logs under Monitor → Logs.

Blob Trigger Test Steps:

1. Open Storage Account → Containers.
2. Upload a file into the correct folder/path.
3. Function will fire automatically.
4. Check logs under Monitor.

Summary

• Postman is ideal for testing API-style HTTP-trigger functions.
• Azure Portal is ideal for quick manual tests after deployment and testing non-HTTP triggers.
• Both tools support verifying input, output, logs, and errors effectively.