Choose Webhook Response Mode Carefully

The n8n Webhook node has two response modes: "Immediately" and "When Last Node Finishes." Immediately acknowledges the caller as soon as the request arrives and processes the workflow afterward; When Last Node Finishes waits for the whole workflow to complete and returns its result. Choosing the wrong mode can either cause the caller to time out or waste resources generating responses nobody reads.

Real-world example: A Shopify webhook sends order events to n8n. Shopify requires a 200 response within 5 seconds or it marks the webhook as failing and will eventually deactivate it. But the workflow takes 30 seconds to fully process the order.

When should you use each webhook response mode?

Scenario 1: Shopify webhooks (fire-and-forget)
  Response Mode: Immediately
  Response Code: 200
  Reason: Shopify doesn't need the processing result, just acknowledgment

Scenario 2: Internal API endpoint called by your frontend
  Response Mode: When Last Node Finishes
  Reason: The frontend needs the processed result to display to the user

Scenario 3: GitHub webhook for CI/CD
  Response Mode: Immediately
  Response Code: 202 (Accepted)
  Reason: GitHub expects fast acknowledgment; results are posted back via Status API

How do you configure the Webhook node for a fire-and-forget webhook?

Webhook node configuration for the Shopify case:

Setting	Value
HTTP Method	POST
Path	/shopify/orders
Response Mode	Immediately
Response Code	200
Response Data	{ "received": true }

Tip: Use Respond to Webhook Node for Custom Responses

If you need to send an immediate acknowledgment but also return data later, place a Respond to Webhook node early in your workflow to send the 200 response, then continue processing in subsequent nodes. This gives you the best of both modes.

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