Square Webhook Tester — Test & Inspect Square Webhooks Online

If you are wiring up Square webhooks, the first question is always the same: what does Square actually send? The docs show an idealised payload, but the real request — its headers, its x-square-hmacsha256-signature header, the exact JSON shape — is what your handler has to parse. A Square webhook tester gives you a public URL that captures those real requests so you can read every byte before you write any code.

Get a free Square webhook tester URL

The fastest way is our free Webhook Bin — a no-code webhook tester that gives you an instant public URL and stores every request that hits it, headers and body included. No signup, no deploy:

1. Open the Webhook Bin and copy the URL it generates for you.
2. In Developer Dashboard → Webhooks → Subscriptions, add a webhook endpoint and paste that URL.
3. Trigger an event (see below) and watch the request land in the bin in real time.

Because the bin keeps the full request, you can inspect the x-square-hmacsha256-signature header, the Content-Type, and the complete payload — the three things you need to build and verify a handler.

What a Square webhook looks like

Square delivers webhooks as an HTTP POST with a application/json body. Square folds the destination URL into the signature, so a stable capture URL is essential — change the URL and the signature changes. Read the captured type field to see which event subscription fired.

A typical payment.created payload looks like this:

{
  "merchant_id": "MLE...",
  "type": "payment.created",
  "event_id": "...",
  "data": {
    "type": "payment",
    "id": "...",
    "object": {
      "payment": {
        "id": "...",
        "amount_money": {
          "amount": 1000,
          "currency": "USD"
        },
        "status": "COMPLETED"
      }
    }
  }
}

Common Square events you will want to test:

• payment.created
• payment.updated
• order.updated
• invoice.payment_made

Verifying the Square signature

Square signs each request so you can prove it really came from Square. The signature travels in the x-square-hmacsha256-signature header and is base64 HMAC-SHA256 over the notification URL concatenated with the raw body, using the subscription's signature key. Capture a real request first, then use our HMAC signature verifier and the verify a webhook signature guide to confirm your verification logic against a payload you can actually see.

From inspecting to receiving on localhost

A bin is perfect for seeing the payload. When you are ready to drive your local handler with real Square events — without deploying — forward them straight to localhost with the Webhook Relay agent. The full walkthrough is here: Receive Square webhooks on localhost.

That gives you a stable public URL that tunnels to your machine, so Square keeps delivering to the same endpoint while you iterate on localhost, no firewall changes or public IP required.

Test Square webhooks online in three steps

1. Capture — point Square at a Webhook Bin URL and inspect the real request.
2. Verify — confirm the x-square-hmacsha256-signature header with the HMAC verifier.
3. Forward — when the shape is clear, receive Square webhooks on localhost and build your handler.

New to webhooks in general? Start with what is a webhook and how to test webhooks.

Ready to inspect your first Square event? Open a free Webhook Bin and paste the URL into Square.