Twilio Webhook Tester — Test & Inspect Twilio Webhooks Online

If you are wiring up Twilio webhooks, the first question is always the same: what does Twilio actually send? The docs show an idealised payload, but the real request — its headers, its X-Twilio-Signature header, the exact JSON shape — is what your handler has to parse. A Twilio 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 Twilio 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 Console → Phone Numbers / Messaging Service webhook fields, 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-Twilio-Signature header, the Content-Type, and the complete payload — the three things you need to build and verify a handler.

What a Twilio webhook looks like

Twilio delivers webhooks as an HTTP POST with a application/x-www-form-urlencoded body. Twilio webhooks are form-encoded, not JSON — and the signature is computed over the URL itself, which is exactly why testing against a stable, captured URL beats guessing from the docs.

A typical incoming SMS payload looks like this:

{
  "MessageSid": "SM...",
  "From": "+15551234567",
  "To": "+15557654321",
  "Body": "Hello world",
  "NumMedia": "0"
}

Common Twilio events you will want to test:

• incoming SMS
• message status callbacks
• voice call status

Verifying the Twilio signature

Twilio signs each request so you can prove it really came from Twilio. The signature travels in the X-Twilio-Signature header and is base64 HMAC-SHA1 over the full URL plus sorted POST params, using your Twilio Auth Token. 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 Twilio events — without deploying — forward them straight to localhost with the Webhook Relay agent. The full walkthrough is here: Receive Twilio webhooks on localhost.

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

Test Twilio webhooks online in three steps

1. Capture — point Twilio at a Webhook Bin URL and inspect the real request.
2. Verify — confirm the X-Twilio-Signature header with the HMAC verifier.
3. Forward — when the shape is clear, receive Twilio 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 Twilio event? Open a free Webhook Bin and paste the URL into Twilio.