Webhooks vs API Polling: Keeping Systems in Sync

What is the difference between webhooks and polling?

Imagine waiting for a parcel. Polling is walking to the door every few minutes to see if it has arrived. A webhook is the courier ringing your doorbell. In integration terms, polling means your application repeatedly calls another system's API asking whether anything has changed, while a webhook means that system calls an address you provide the moment something happens.

Both keep systems in sync, but they differ in who initiates the conversation. Polling puts the burden on you: you decide the frequency and pay the cost of every check. Webhooks put it on the sender, and you must be ready to receive messages at any moment.

What are the strengths and weaknesses of polling?

Polling is simple. You need no public endpoint, and you control timing and load. It works with any API that offers a way to list or fetch records, and it is easy to understand and debug. For data that changes rarely, a scheduled check every few minutes or hours is perfectly adequate.

The weaknesses show at scale. Frequent polling wastes calls when nothing changed, may hit rate limits, and still introduces a delay between the event and your discovery of it. Poll too rarely and the data is stale; poll too often and you burn resources and risk being throttled by the provider.

• Simple to build and test.
• No public endpoint required.
• You control the schedule and load.
• Delay between event and detection.
• Wasted requests when nothing has changed.

What are the strengths and weaknesses of webhooks?

Webhooks deliver news immediately and efficiently. A payment gateway tells you the instant a UPI payment succeeds; a messaging platform tells you when a customer replies. You make no wasted calls and can trigger actions, such as confirming an order or alerting a salesperson, with minimal delay.

They also add responsibilities. Your endpoint must be publicly reachable, respond quickly, and be secured. Senders typically retry on failure, so you may receive the same event more than once, and events can arrive out of order. If your server is down during delivery, you can miss events unless the sender keeps retrying or you reconcile later.

• Near real-time updates.
• Efficient, with no empty checks.
• Needs a secure, reachable endpoint.
• Duplicates and retries must be handled.
• Events may arrive late or out of order.

How do you make a webhook receiver reliable?

First, verify authenticity. Most providers sign each request with a secret so you can confirm it truly came from them, and you should reject anything that fails the check. Second, respond fast: acknowledge the request quickly and place the real work on a queue, so slow processing does not cause timeouts and retries.

Third, be idempotent. Store each event's unique identifier and ignore repeats, so a duplicate payment notification never credits an account twice. Log everything, and keep the raw payload for debugging. Treat webhook handling like financial plumbing: small, strict and observable.

Why combine webhooks with polling?

No delivery system is perfect. Networks fail, servers restart during deployments and providers occasionally drop events. A reconciliation job that polls the provider periodically, for example fetching all payments from the last day and comparing them with your records, catches anything the webhooks missed.

This belt-and-braces approach is common in payments, orders and inventory. Webhooks give you speed for the normal case, and polling gives you certainty for the exceptions. The result is data you can trust, which matters whenever money or stock is involved.

How do you choose for your use case?

If the provider offers webhooks and timeliness matters, use them, ideally with reconciliation. If it offers none, or the data changes slowly, polling is fine. For internal tools behind a firewall that cannot receive inbound calls, polling may be the only practical option.

Document each integration: which events you listen to, how you verify them, how failures are retried and who is alerted. Clear monitoring, such as alerts when no events arrive for an unusual period, turns a hidden failure into a quick fix.

Frequently asked questions

Are webhooks always better than polling?

No. They are faster and more efficient for events, but polling is simpler and works where webhooks are unavailable. Many systems use both.

What happens if my server is down when a webhook is sent?

Many providers retry for a period, but not all do forever. A periodic reconciliation check protects you from missed events.

How do I secure a webhook endpoint?

Verify the provider's signature, use HTTPS, restrict what the endpoint can do and log requests. Never trust unverified payloads.

How often should I poll?

Match it to how fresh the data must be and to the provider's rate limits. Avoid very short intervals unless needed.

Need help with this? See our API Development & Integrations service or talk to Yash Parikh.