When I first started learning backend development, I kept hearing two terms everywhere:
- Polling
- Webhooks
At first they sounded complicated, but the core idea is simple.
Both are ways for one system to get updates from another system.
The difference is who starts the communication.
What is Polling?
Polling means your application repeatedly asks another server for updates.
Something like:
“Any new updates?”
“Any updates now?”
“What about now?”
Example:
setInterval(() => {
fetch("/api/status");
}, 5000);
Here, the client checks every 5 seconds.
Real-life Example of Polling
Think about checking your job application status on a company portal.
You log in and see:
Status: Under Review
After 3 days, you refresh the page.
Your browser sends another API request asking:
Has my application status changed?
That refresh is basically manual polling.
Why Polling Can Be Inefficient
Polling is easy to implement, but there’s a problem.
What if nothing changes for hours?
Your application still keeps sending requests.
That means:
- Extra server load
- Unnecessary network calls
- Wasted resources
Imagine 50,000 users checking every few seconds.
That becomes expensive.
What is a Webhook?
Webhook solves this problem.
Instead of repeatedly asking for updates, you provide your server URL to another service.
When something happens, that service sends data automatically.
In simple words:
Don’t ask me repeatedly — I’ll notify you when something changes.
Real-life Example of Webhook
Payment systems are the best example.
Suppose a customer pays using Stripe or Razorpay.
Without webhooks, your backend keeps asking:
Payment successful?
With webhooks, the payment provider instantly sends a request to your server.
Example payload:
{
"event": "payment.success",
"orderId": 101
}
Your backend can then:
- Mark order as paid
- Generate invoice
- Send confirmation email
All automatically.
Polling vs Webhook
| Feature | Polling | Webhook |
|---|---|---|
| Communication | Client asks repeatedly | Server pushes updates |
| Speed | Delayed | Near real-time |
| Requests | More | Less |
| Scalability | Lower | Better |
Simple Analogy
Imagine ordering food.
Polling
You call the restaurant every 5 minutes:
“Is my food ready?”
Webhook
Restaurant calls you when food is ready.
That’s the difference.
Final Thoughts
Use Polling when:
- Data changes slowly
- Simplicity matters
- Real-time updates are not required
Use Webhooks when:
- Events happen unpredictably
- Instant updates matter
- Scalability is important
Polling is pull-based communication.
Webhooks are push-based communication.
Top comments (1)
Thank you, now it is clearly understandable!