Twilio Webhook Testing — Debug Twilio Events Instantly

To test Twilio webhooks, you need a public HTTPS endpoint that Twilio can POST to. WebhookWhisper gives you one instantly — no CLI, no deployment, no ngrok required. Paste the URL into your Twilio dashboard, trigger a test event, and inspect the full payload in real time.

Why Test Twilio Webhooks with WebhookWhisper?

Twilio sends webhook callbacks for SMS messages, voice calls, and WhatsApp events. Every request is signed with HMAC-SHA1 for security.

WebhookWhisper captures every incoming Twilio event with full headers, body, and timing data — so you can debug integration issues without deploying to a public server.

Twilio Webhook Events

The following events are commonly sent by Twilio:

• message.received
• message.delivered
• call.initiated
• call.completed
• call.failed

How to Test Twilio Webhooks Locally

1. Create your endpoint — Sign up free and get a permanent HTTPS URL in seconds.
2. Add the URL to Twilio — Paste your WebhookWhisper URL into your Twilio webhook settings.
3. Enable forwarding (optional) — Add a forwarding rule to relay events to localhost:3000 or any local port.
4. Trigger a test event — Use Twilio's dashboard or the one-click test sender to fire a message.received event.
5. Inspect in real time — See the full payload, headers, and response in your WebhookWhisper dashboard.

Twilio Webhook Signature Verification

Twilio signs every webhook request using the X-Twilio-Signature header. Always verify this signature in production to prevent spoofed requests.

// Node.js — Verify Twilio webhook signature
const crypto = require('crypto');

function verifyTwilioSignature(payload, signature, secret) {
  const expected = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');
  return crypto.timingSafeEqual(
    Buffer.from(expected),
    Buffer.from(signature)
  );
}

Common Twilio Webhook Errors

• 401 Unauthorized — Signature mismatch. Check that you are using the raw request body (not parsed JSON) for HMAC verification.
• Webhook not received — Verify the URL is publicly accessible. WebhookWhisper endpoints are always public — no tunneling needed.
• Timeout errors — Twilio expects a 2xx response within a few seconds. Respond immediately and process the event asynchronously.
• Duplicate events — Twilio retries webhook requests up to 4 times if your endpoint returns a non-2xx response. Always use the event ID for idempotency checks.

Frequently Asked Questions

How do I test Twilio webhooks for free?

Sign up for a free WebhookWhisper account and get a permanent HTTPS endpoint. Add it to your Twilio webhook settings and trigger a test event from the Twilio dashboard.

Can I test Twilio webhooks without deploying?

Yes. WebhookWhisper gives you a public HTTPS URL that requires no deployment. Use the built-in forwarding rules to relay events to your local development server.

How do I receive Twilio webhooks on localhost?

Create a forwarding rule in WebhookWhisper pointing to your local port (e.g. http://localhost:3000/webhook). Every incoming event is relayed to your local server with retry logic.

What is the Twilio webhook retry policy?

Twilio retries webhook requests up to 4 times if your endpoint returns a non-2xx response.