Webhooks vs. Polling – Definition and Differences
Compare push and pull integration on latency, cost, reliability, and operational burden — and see why robust systems use both.
Polling asks repeatedly whether anything changed. Webhooks are told when something does. The trade is latency and request volume against operating a public endpoint.
1. Key Differences
| Dimension | Polling | Webhooks |
|---|---|---|
| Direction | You call them | They call you |
| Latency | Up to the poll interval | Near-immediate |
| Cost when idle | Requests continue regardless | Nothing |
| Infrastructure | A scheduled job | A public HTTPS endpoint |
| Missed events | Caught on the next poll | Need retries and reconciliation |
| Ordering | You control it | Not guaranteed |
| Debugging | Re-run the poll | Replay from provider logs |
2. Why Polling Persists
It is simple and forgiving. There is no endpoint to expose, no signature to verify, no redelivery to handle, and a missed run self-corrects on the next one.
For anything where minutes of latency are acceptable, polling is frequently the right answer despite looking less sophisticated.
3. Why Webhooks Win on Cost and Latency
Polling a resource that changes rarely spends nearly all its requests learning nothing. Webhooks reverse that: traffic occurs only when something happened.
For high-volume, low-change data, the difference is large — and the latency improvement is often the more visible benefit.
4. What Webhooks Demand
- An always-available public endpoint.
- Signature verification, computed over the raw body.
- Idempotency, because delivery is at-least-once.
- Fast acknowledgement, with real work done asynchronously.
- Tolerance of out-of-order arrival.
- A reconciliation path, since retries can be exhausted.
That last item is what people skip, and it is why a webhook-only integration eventually loses data.
5. Conditional Polling Narrows the Gap
Polling need not be wasteful. ETag and If-Modified-Since let a server answer "nothing changed" cheaply, and many APIs expose a changes endpoint returning only what moved since a cursor.
A well-implemented conditional poll costs far less than a naive one and keeps all of polling's simplicity.
6. The Robust Pattern Is Both
Webhooks for latency, plus a periodic reconciliation poll to catch what redelivery missed.
The poll runs at a low frequency and compares state rather than reacting to events. It is the safety net that makes webhook-driven data trustworthy, and it costs very little.
7. Choosing
- Latency in seconds required? Webhooks, with reconciliation.
- Minutes acceptable? Polling, made conditional.
- No public endpoint possible? Polling.
- Very high event volume? Webhooks — polling cannot keep up.
- Data that must never be missed? Both.
8. Summary
Polling is simple, self-correcting, and wasteful when little changes. Webhooks are immediate and efficient, and demand an endpoint, verification, idempotency, and a reconciliation path.
Production integrations that matter usually run webhooks for latency and a periodic poll for completeness, because the second is what makes the first dependable.