Every integration eventually asks the same question: do I ask for data or wait to be told? Polling and webhooks are both valid answers — and picking the wrong one quietly kills your app's performance, reliability, or developer experience. This is the 2026 guide that cuts through the hype.
What changed in 2026
- Webhook tooling matured. Services like Svix and Hookdeck handle delivery, retries, and replay out-of-the-box, so the "webhooks are hard to operate" objection is largely dead.
- HTTP/3 and QUIC reduced the overhead of persistent connections, making WebSockets and SSE cheaper to run at scale.
- Edge runtimes (Cloudflare Workers, Fastly Compute) mean you can receive webhooks at 50 ms global p99 without managing a fleet.
- Cost awareness returned — teams now count egress and compute per event; aggressive polling shows up fast on cloud bills.
The core distinction
Polling means your client asks the server "anything new?" on a fixed interval. The server responds immediately, even if the answer is "no."
Webhooks flip the direction: the server calls your endpoint the moment an event happens. You must expose a publicly reachable URL and handle the payload.
Both deliver the same data; only the direction and timing differ.
Latency and cost comparison
| Strategy |
Typical latency |
Requests for 1 event |
Good for |
| Polling (60 s interval) |
0–60 s |
~60 per event |
Batch jobs, non-critical sync |
| Polling (5 s interval) |
0–5 s |
~720/hr |
Moderate freshness |
| Polling (1 s interval) |
0–1 s |
~3,600/hr |
Expensive, rarely justified |
| Long-polling |
~1–2 s |
1 per event |
Medium freshness, NAT-friendly |
| Webhooks |
<500 ms |
1 per event |
Real-time, low overhead |
| SSE |
<100 ms |
1 open stream |
Dashboards, live feeds |
| WebSocket |
<50 ms |
1 open socket |
Bidirectional real-time |
What changed in 2026
Webhook delivery services now charge ~$0 for the first million deliveries per month (Svix free tier), and signing + replay is standard. The cost argument for polling over webhooks has mostly evaporated for normal workloads.
How to pick
- Event is rare and you need it fast → Webhook. One delivery, near-zero cost.
- You are behind a firewall or NAT → Long-polling or SSE (server pushes to your open connection).
- You need bidirectional real-time → WebSocket.
- The source never offers webhooks → Poll, but cache aggressively.
- Batch ETL, data warehouse loads → Poll on a schedule (hourly, daily). Webhooks add no value here.
- You own both sides → SSE or WebSocket; skip the webhook round-trip entirely.
Webhook implementation checklist
// Verify Svix signature before processing
import { Webhook } from "svix";
const wh = new Webhook(process.env.WEBHOOK_SECRET!);
const payload = wh.verify(rawBody, {
"svix-id": req.headers["svix-id"] as string,
"svix-timestamp": req.headers["svix-timestamp"] as string,
"svix-signature": req.headers["svix-signature"] as string,
});
// idempotency: store payload.id, skip if already seen
Always verify the signature. Always respond 200 quickly and process async. Always deduplicate by event ID.
Polling implementation checklist
// Cursor-based polling — only fetch what changed
let cursor = await getLastCursor();
while (true) {
const { events, nextCursor } = await api.events({ after: cursor });
for (const e of events) await process(e);
cursor = nextCursor;
await sleep(5_000);
}
Use a cursor or updated_since timestamp — never fetch full lists on every tick.
Common mistakes
Polling at 1-second intervals. You are hammering the server for events that arrive once a minute. Use webhooks or at minimum back off exponentially when the response is empty.
Not verifying webhook signatures. Anyone can POST to your endpoint. Verify HMAC-SHA256 on every request before touching the payload.
Synchronous webhook processing. If your handler takes >5 s the sender retries and you process duplicates. Return 200 immediately, enqueue the work.
No idempotency key. Webhooks retry on network errors. You will receive the same event twice. Store the event ID and skip re-processing.
Ignoring the retry schedule. Most senders back off exponentially. Know the retry window (often 72 h) and design your recovery accordingly.
What to skip
- Sub-second polling for anything but a game server. It is nearly always wrong and very expensive.
- Building your own webhook delivery layer. Use Svix, Hookdeck, or Inngest in 2026; the problem is solved.
- Polling an API that already supports webhooks. Stripe, GitHub, Twilio, and virtually every modern API publish events; use them.
FAQ
Can I use both at once?
Yes — a common pattern is: webhooks for real-time updates, polling as a reconciliation fallback to catch missed events.
What if the webhook endpoint is down?
Reputable senders retry with exponential backoff for 24–72 h. Build a dead-letter mechanism and monitor delivery failures.
Is long-polling still relevant?
Yes, especially for mobile apps that may be behind restrictive NAT or for clients that cannot hold a persistent TCP connection reliably.
How do I test webhooks locally?
Use ngrok, Cloudflare Tunnel, or the Stripe CLI (stripe listen --forward-to localhost:3000/webhook). All three work well in 2026.
Where to go next