This error means Make sent a webhook request to an external app but did not receive a response within the timeout period. The external app may be down, the webhook URL may be wrong, or the app is taking too long to respond. Verify the webhook URL, check that the external app is running, and increase the timeout if the app needs more processing time.
What does "App not responding to webhook" mean in Make?
When Make shows "App not responding to webhook," it means a webhook module in your scenario sent an HTTP request to an external application and the application either did not respond at all or did not respond within Make's timeout window. Make expects the receiving app to send back an HTTP response within 40 seconds (the per-module timeout), and silence beyond that triggers this error.
This error falls under Make's ConnectionError category, which covers all cases where Make cannot establish or maintain communication with an external service. It can indicate the external app is completely down, the webhook URL has changed, a firewall is blocking Make's requests, or the app is alive but processing takes longer than 40 seconds.
Make's webhook system also has a queue limit — if 50 webhook events pile up without being processed, new webhooks return HTTP 400 "Queue is full." This queue overflow can cause the sending app to think its webhooks are failing when the issue is actually on Make's processing side.
Common causes
The external app receiving the webhook is
down, offline, or experiencing an outage
The webhook URL is incorrect, expired, or
was regenerated without updating the Make scenario
A firewall, CDN, or security tool is
blocking incoming requests from Make's IP addresses
The external app takes longer
than 40 seconds to respond, exceeding Make's per-module timeout
Make's webhook queue (50 items)
overflowed because the scenario was paused or processing slowly
The external app requires authentication headers that
are not included in the webhook request
How to fix webhook response failures in Make
First, verify the webhook URL is correct by testing it directly. Copy the webhook URL from your Make scenario and send a test request using a tool like Postman or curl. If the external app responds to your test but not to Make, check the app's firewall rules to ensure Make's IP addresses are allowed (Make publishes their IP ranges in their documentation).
If the app is slow to respond, consider restructuring your scenario to not require a synchronous webhook response. Instead of waiting for the app to process and respond, have the app acknowledge the webhook immediately (return HTTP 200) and process the data asynchronously. For Make's incoming webhooks, increase the processing speed by keeping your scenario simple and fast. If the webhook queue fills up regularly, add a second webhook URL as a backup. For complex webhook integrations that keep failing, RapidDev can help design a reliable event-driven architecture.
Prevention tips
- Test webhook URLs directly with Postman or curl to isolate whether the issue is with Make or the external app
- Whitelist Make's published IP ranges in your external app's firewall to prevent blocked requests
- Design webhook receivers to respond immediately with HTTP 200 and process data asynchronously to avoid timeout errors
- Monitor your Make webhook queue — if it frequently fills up, increase your scenario's execution frequency or add parallel processing
Still stuck?
Copy one of these prompts to get a personalized, step-by-step explanation.
My Make (Integromat) scenario shows 'App not responding to webhook'. The external app is running but Make cannot reach it. How do I diagnose the connection issue?
Check my Make webhook configuration and suggest fixes for why the external app is not responding to webhook requests within the timeout period.
Frequently asked questions
Why does Make show "App not responding to webhook" even though my app is online?
The app may be online but blocking Make's requests. Check your app's firewall, security middleware, and rate limiting. Also verify that the webhook URL in Make matches the current URL in your app — URLs change when apps are redeployed.
What is Make's timeout for webhook responses?
Make has a 40-second per-module timeout (ModuleTimeoutError) and a 40-minute overall scenario timeout. If your external app takes longer than 40 seconds to respond, the webhook module will fail.
How do I test a Make webhook URL manually?
Copy the webhook URL from your Make scenario, then use Postman, curl, or any HTTP client to send a POST request with sample JSON data to that URL. Check if Make receives and processes the request.
What happens when Make's webhook queue is full?
When the default queue of 50 items overflows, Make returns HTTP 400 'Queue is full' to the sender. The sending app will not be able to deliver new webhook events until Make processes the queued items.
Can Make's IP addresses be whitelisted in my app's firewall?
Yes. Make publishes their IP address ranges in their documentation. Add these IPs to your app's firewall allowlist to ensure Make can reach your webhook endpoints.
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