A webhook is an automatic message that one piece of software sends to a web address in another the moment a particular event happens, such as a new order, a form submission or a cancelled booking. Instead of the second system repeatedly asking “anything new?”, the first one tells it straight away.
How a webhook works
Setting up a webhook has two sides. The receiving system provides a URL, sometimes called the endpoint, that is ready to accept messages. In the sending system, you paste that URL into its webhook settings and choose which events should trigger a message.
When the event happens, the sender makes an HTTP request (usually a POST) to the URL, carrying a payload: a structured bundle of data, normally in JSON format. A Shopify “order created” webhook, for example, carries the order number, products, totals and customer details. The receiver reads the payload and does something with it, such as adding the buyer to an email sequence or posting a message to a team channel.
Webhooks are closely related to an API. With a normal API call, your system asks another for data when it wants it. A webhook reverses the direction: the other system pushes data to you when something changes. Many automations use both: a webhook announces the event, then an API call fetches any extra details.
No-code tools make this approachable. Zapier and Make both offer a “catch webhook” step that generates a URL for you, which can act as the trigger for a whole workflow.
Why it matters
Speed is the main benefit. A lead that arrives through your website form at 10:02 can be in your CRM, assigned to a salesperson and acknowledged by email by 10:03. Polling every 15 minutes, or exporting a spreadsheet each morning, means slower replies, and enquiries tend to go cold quickly when a competitor answers first.
Webhooks also connect tools that have no direct integration. A booking system, a payment provider and an accounting package that have never heard of each other can still be linked if each can send or receive webhooks. For ad tracking, webhooks from a CRM are a common way to tell you when a lead becomes a sale, so that offline conversions can be sent back to Google Ads or Meta.
There is a data protection side. Payloads often contain names, emails and phone numbers. Sending them to an endpoint is a transfer of personal data, so the receiving service needs to be covered by your privacy notice and processor terms like any other tool.
Common mistakes
- No verification. Anyone who discovers an endpoint URL could send fake data to it. Most platforms sign their webhooks with a shared secret; check the signature before trusting the payload.
- Personal data in the URL. Query strings end up in server logs. Keep personal details in the body of the request, over HTTPS.
- No handling for repeats. Senders retry when they do not get a quick success response, so the same event can arrive twice. Use the event ID to ignore duplicates.
- Silent failures. If the receiving end breaks, events may be lost after the retry period. Set up alerts for failed deliveries.
- Slow processing. Doing heavy work before replying can cause timeouts and retries. Acknowledge first, process afterwards.
How to act on it
Start by listing the moments in your business where speed matters: new enquiries, new orders, cancellations, failed payments. Check whether the system where each event happens offers webhooks, and what event types it supports.
For a first build, use a no-code catch-webhook step, send a test event, and inspect the payload so you know exactly which fields arrive. Add signature checks, duplicate handling and a failure alert before relying on it. Mapping which events should flow between your marketing tools, and why, is part of the digital marketing strategy work I do. For the wider picture, see REST API for how most web services expose their data.