A webhook is an automatic message one app sends to a URL you provide when a specific event happens, such as a new payment or form submission. With an API you ask for data; with a webhook the app tells you immediately. Webhooks power real-time automations and are widely used in tools like n8n, Make and Zapier.
Pull versus push
- API (pull): your system asks, "Any new orders?" You must keep asking, which is called polling.
- Webhook (push): the other system says, "A new order just arrived, here are the details," the moment it happens.
Think of the difference between repeatedly checking your door for a parcel and getting a doorbell ring when it arrives.
How a webhook works
- You create a URL that can receive data, called a webhook endpoint. Automation tools give you one with a single click.
- You register that URL in the other app's settings and choose which events to send, such as "payment succeeded".
- When the event happens, the app sends an HTTP
POSTrequest to your URL with event data, usually in JSON. - Your system processes the data and responds with a success code.
Real examples
- A payment provider notifies your system when a payment succeeds or fails.
- A form tool sends each submission to your automation.
- A booking system sends new appointments to your CRM.
- A code repository notifies a build server when code is pushed.
Webhooks in automation tools
In n8n, the Webhook node gives you a URL to paste into another service. In Zapier and Make, "Catch hook" or "Custom webhook" triggers do the same. Once you understand webhooks, you can connect almost any app that supports them, even without a ready-made integration. See n8n for beginners.
Security tips
- Keep URLs private. Anyone with the URL could send fake data.
- Verify signatures. Many services sign webhook requests; check the signature to confirm the source.
- Validate data before acting on it.
- Handle duplicates. Services sometimes resend events; make your workflow safe to run twice.
- Respond quickly, and do heavy processing afterwards, to avoid timeouts.
Frequently asked questions
Is a webhook a type of API?
It uses the same web technology, HTTP requests, but in the reverse direction. Some people call webhooks "reverse APIs".
Do I need a server to receive webhooks?
Automation platforms provide hosted webhook URLs, so beginners do not need their own server.
What if my system is down when a webhook is sent?
Many services retry for a period. Check each provider's retry behaviour.
