Webhooks vs Polling
Every automation has to answer one question: how do I find out that something happened? There are two answers, keep asking (polling), or get told (webhooks), and the choice shapes latency, cost, and reliability.
Polling: ask, repeatedly
With polling, your code checks the source on a schedule: “any new orders?” every minute, forever. It’s simple and works against almost anything, if a service has an API you can read, you can poll it, no special setup required. The downsides are built in:
- Latency: you only learn about an event at the next check, so your delay is as long as your interval. Poll every 5 minutes and news can be 5 minutes stale.
- Waste: the vast majority of checks find nothing and return empty, burning requests, bandwidth, and often rate limit budget for no result.
Polling faster cuts latency but multiplies the waste, that tension is the whole problem with polling.
Webhooks: get told, instantly
A webhook inverts the relationship. Instead of you asking, the source pushes a message to a URL you provide, the moment something happens. It’s essentially “don’t call us, we’ll call you.” The payoff is the inverse of polling’s pain:
- Real-time: you hear about the event as it occurs, not at the next interval.
- Efficient: one request per actual event, no empty checks.
But pushing has its own requirements:
- You need a public endpoint for the source to reach, a hosted URL (a server, a serverless function, or an automation platform that receives it for you).
- You must handle the messy parts of delivery: a webhook can be sent twice (so handle it idempotently), or missed if your endpoint is down, and you should verify the signature so you know the message is genuine and not a forged request.
Side by side
- Latency: webhook is near-instant; polling is up to one interval behind.
- Efficiency: webhook sends one message per event; polling makes many empty calls.
- Setup: polling needs only read access; webhooks need a public endpoint and the source must support them.
- Reliability: polling naturally re-checks, so a missed beat self-heals; a missed webhook is simply gone unless the sender retries.
When to use which
Prefer webhooks when the source supports them and you can host an endpoint, especially at scale or when freshness matters. Fall back to polling when the source has no webhooks, when you can’t expose a public URL, or when a few minutes of delay simply doesn’t matter. Many robust systems do both: take webhooks for speed, and run a slow periodic poll to reconcile, catching anything a webhook dropped. It’s a common, honest belt-and-suspenders pattern.
FAQ
Which one is better?
Neither universally. Webhooks win on latency and efficiency; polling wins on simplicity and works everywhere. The right call depends on whether the source supports webhooks, whether you can host an endpoint, and how fresh the data needs to be.
Can I use webhooks without running a server?
Yes, indirectly. You still need something to receive the request, but it can be a serverless function or a no-code platform (Zapier, Make, n8n) that exposes a catch-hook URL and runs your steps when it fires.
Why did my webhook arrive twice?
Senders retry when they’re unsure a delivery succeeded, so duplicates are normal. Design the receiving step to be idempotent, using the event’s ID to ignore a repeat, so processing the same event twice has no extra effect.
Related
Webhooks and schedules are the two triggers behind workflow automation. Build a polling schedule with the cron generator, or browse AI Explained.