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How to Test Webhooks in Zapier

See the exact HTTP Zapier sends: Webhooks by Zapier POST, paste an inspector URL, test the action, and read method, headers, and body.

By David Lorenzo García··5 min read

Zapier can send a webhook (your URL) or catch one (Zapier’s URL). OpenWebhook is for the send path: you want the raw request Zapier actually posts. A Catch Hook already shows the inbound payload inside Zapier; do not replace that URL with an inspector.

Get a live URL from the webhook inspector. Keep the tab open. Details of the three-step inspector loop are in how to test webhooks online.

Webhooks by Zapier → POST

  1. Create a Zap. After the trigger, add Webhooks by Zapier.
  2. Choose POST (JSON) or Custom Request if you need another method.
  3. Paste the inspector URL:
https://hooks.openwebhook.co/YOUR_UUID/zapier
  1. Map fields into the payload. Set Content-Type to application/json unless you are sending form data.
  2. Click Test on that action (not only on the trigger).

You should see POST /zapier, Zapier’s User-Agent, the headers you set, and the JSON body. Copy cURL from the inspector if you need to replay it against a local handler.

Custom Request

Use Custom Request when the destination expects PUT/PATCH, a raw body, or extra headers (HMAC, X-Api-Key). Test once with the inspector, then point the same step at your real API.

When to use the CLI

If the next hop is a process on 127.0.0.1, run openwebhook listen and put the printed HTTPS URL in the Zapier action. While listen is connected, the public response is whatever localhost returned.

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