A complete, beginner-friendly guide to webhooks — how they work, why they matter, and how to use them securely.
A webhook is an HTTP callback: when an event occurs in a source application (like a payment succeeding in Stripe), it sends an HTTP POST request to a URL you've configured. Your application receives the request, processes the data, and responds with a 200 OK.
Here's what a typical webhook payload looks like (Stripe payment example):
{
"type": "payment_intent.succeeded",
"data": {
"object": {
"id": "pi_3abc123",
"amount": 2000,
"currency": "usd",
"status": "succeeded"
}
}
}The traditional alternative to webhooks is polling — your app repeatedly calls an API to check for updates. Here's how they compare:
| Aspect | Webhook (push) | API Polling (pull) |
|---|---|---|
| Data delivery | Instant, real-time | Delayed (depends on poll interval) |
| Server load | Minimal — only fires on events | High — constant requests even when idle |
| API rate limits | Not consumed | Consumed on every poll |
| Implementation | Requires a public endpoint | Simple GET requests |
| Reliability | Needs retry logic for failures | Client controls retry |
| Cost at scale | Pays only for real events | Pays for every empty poll |
Bottom line: Webhooks are almost always the better choice for real-time, event-driven integrations. Polling is simpler to set up but wasteful and slow.
Get notified instantly when a payment succeeds, fails, disputes, or refunds. Update your database and trigger fulfillment without delay.
Trigger builds, tests, and deployments automatically when code is pushed, a PR is merged, or a release is tagged.
Sync orders, inventory, and customer data in real time. Automate shipping notifications and warehouse fulfillment.
React to incoming messages, delivery confirmations, bounces, and status changes as they happen.
Keep data synchronized across tools. Update your CRM when a support ticket closes, or notify a channel when a deal moves stages.
Webhooks involve accepting HTTP requests from external sources, so security is critical. Here are the essentials:
Most providers (Stripe, GitHub, Shopify) sign webhook payloads with HMAC-SHA256. Always verify the signature before processing. This prevents spoofed requests.
Never accept webhooks over plain HTTP. TLS encrypts the payload in transit and prevents man-in-the-middle attacks.
Check that the webhook timestamp is recent (within 5 minutes). This prevents replay attacks where an attacker re-sends a captured request.
Restrict your webhook endpoint to accept requests only from your provider's published IP ranges. Block everything else.
Return a 200 OK immediately and process the webhook asynchronously in a background job. This prevents timeouts and retry storms.
Review your endpoint against the manual webhook security checklist, including signature validation, replay protection, TLS, rate limits, and log redaction.
For a deeper dive into webhook security threats and defenses, read our Webhook Security Best Practices guide.
During development, you need a way to receive webhooks on your local machine. Here's a quick approach:
Get a free endpoint URL instantly. No signup required. See every header and byte that arrives.
Open Webhook Tester Review Security ChecklistRelated guides: Webhook vs API · Webhook Security · Retry Strategies
More: Webhook Security Guide | All Features | Stripe Webhook Guide | Compare Tools