Delay between requests in Postman - Build an Automation Script

Add delay between API requests in Postman collection

Preconditions (2)

Step 1: Open the Postman collection with multiple requests

Step 2: Select the first request in the collection

Step 3: Go to the Tests tab of the first request

Step 4: Add a script to pause execution for 3 seconds before the next request runs

Step 5: Save the script

Step 6: Run the collection using the Collection Runner

Step 7: Observe that there is a 3-second delay between the first and second request

✅ Expected Result: The collection runner pauses for 3 seconds between the first and second requests, delaying the next request execution as scripted.

Automation Requirements - Postman scripting (JavaScript)

Assertions Needed:

Verify that the delay script executes without errors

Verify that the delay causes a pause of approximately 3 seconds between requests

Best Practices:

Use pm.setNextRequest(null) to control request flow if needed

Use setTimeout or async/await with Promises for delay

Keep scripts simple and readable

Avoid hardcoding delays longer than necessary

Automated Solution

Postman

pm.test('Delay 3 seconds before next request', function(done) {
    setTimeout(() => {
        done();
    }, 3000);
});

This script is added in the Tests tab of the first request. It uses pm.test with a callback done to create an asynchronous test. Inside, setTimeout waits for 3000 milliseconds (3 seconds) before calling done(), which tells Postman to continue to the next request. This effectively adds a 3-second delay between requests during collection run.

This approach is simple and uses Postman's built-in asynchronous test handling to pause execution without blocking the UI.

Common Mistakes - 3 Pitfalls

Using synchronous loops or blocking code to create delay

Placing delay script in Pre-request Script tab instead of Tests tab

Not calling done() in asynchronous test, causing timeout

Bonus Challenge

Now add data-driven testing with 3 different delay durations (1s, 3s, 5s) for the delay between requests

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