Webhooks vs WebSockets: A Developer's Decision Guide

Webhooks and WebSockets both push data in real time, but they solve fundamentally different problems. Webhooks are HTTP callbacks between servers — one system notifies another when an event occurs. WebSockets are persistent connections between a server and a client — data flows in both directions as long as the connection stays open. For a comparison of webhooks against the pull model, see webhooks vs polling. For a broader look at push vs request-response patterns, see webhooks vs APIs.

Choosing wrong does not just cost performance. It costs engineering time — building retry infrastructure you did not need, or scaling stateful connections you could have avoided.

How webhooks work

A webhook is an HTTP callback. When an event occurs on the source system, it sends an HTTP POST to a URL you registered. The request contains a payload describing the event. Your server processes it and returns a status code.

// Stripe sends a webhook when a payment succeeds
app.post('/webhooks/stripe', (req, res) => {
  const event = req.body;

  // Verify signature first
  const sig = req.headers['stripe-signature'];
  const verified = stripe.webhooks.constructEvent(req.body, sig, endpointSecret);

  if (verified.type === 'payment_intent.succeeded') {
    activateSubscription(verified.data.object.customer);
  }

  res.status(200).send('OK');
});

The connection opens, delivers the payload, and closes. There is no persistent state between deliveries. Each webhook is an independent HTTP request.

Webhook characteristics

• Transport: Standard HTTP/HTTPS (POST requests)
• Connection: One request per event, no persistent connection
• Direction: Unidirectional — source pushes to receiver
• State: Stateless — each delivery is independent
• Delivery model: At-least-once with retries
• Receiver: A server with a publicly accessible URL

How WebSockets work

WebSockets start as an HTTP request that upgrades to a persistent, full-duplex TCP connection. Once established, either side can send messages at any time without the overhead of new HTTP requests.

// Browser connects to a WebSocket server for live notifications
const ws = new WebSocket('wss://app.example.com/ws/notifications');

ws.onopen = () => {
  // Authenticate after connection
  ws.send(JSON.stringify({ type: 'auth', token: sessionToken }));
};

ws.onmessage = (event) => {
  const data = JSON.parse(event.data);

  if (data.type === 'new_order') {
    updateDashboard(data.order);
  }

  if (data.type === 'price_update') {
    renderNewPrice(data.ticker, data.price);
  }
};

ws.onclose = () => {
  // Reconnect with exponential backoff
  setTimeout(connect, retryDelay);
  retryDelay = Math.min(retryDelay * 2, 30000);
};

The connection stays open for minutes, hours, or days. Messages flow in both directions with minimal framing overhead — no HTTP headers on every message.

WebSocket characteristics

• Transport: Persistent TCP connection (upgraded from HTTP)
• Connection: Long-lived, maintained by heartbeats/pings
• Direction: Bidirectional — both sides send and receive
• State: Stateful — server tracks each connected client
• Delivery model: Best-effort (messages lost if connection drops)
• Receiver: A browser, mobile app, or any WebSocket client

Side-by-side comparison

When to use webhooks

Webhooks are the right choice when the receiver is a server, events are relatively infrequent, and reliability matters more than latency.

Event notifications between services

Payment processor notifying your backend about a successful charge. Shipping provider updating order status. Git hosting service telling your CI pipeline about a push. These are server-to-server notifications where the receiver processes the event asynchronously.

# Your server receives a webhook from a payment provider
@app.route('/webhooks/payments', methods=['POST'])
def handle_payment_webhook():
    verify_signature(request)
    event = request.json

    if event['type'] == 'charge.succeeded':
        queue.enqueue('fulfill_order', order_id=event['data']['order_id'])

    return '', 200

The payment provider does not need a persistent connection to your server. It needs to deliver a message and know it was received. If delivery fails, it retries with exponential backoff. This retry mechanism is what gives webhooks their reliability advantage.

Infrequent events

If events happen a few times per hour — or a few times per day — maintaining a persistent WebSocket connection is wasteful. The connection sits idle 99.9% of the time, consuming server memory and requiring heartbeat pings to stay alive.

Webhooks have zero cost when nothing is happening. You only pay (in compute) when an event actually occurs.

Cross-network communication

Webhooks work across firewalls, NATs, and cloud boundaries because they are standard HTTPS POST requests. The receiver just needs a publicly accessible URL. No special network configuration, no persistent connection through proxies.

When to use WebSockets

WebSockets are the right choice when the receiver is a browser or mobile app, events are frequent, and latency must be minimal.

Real-time user interfaces

Chat applications, collaborative editors, live dashboards, multiplayer games — any feature where users expect to see changes the instant they happen. A stock trading dashboard that updates every 50 milliseconds cannot afford the overhead of establishing a new HTTP connection for each price tick.

// Server pushing live price updates to connected traders
wss.on('connection', (ws, req) => {
  const userId = authenticate(req);
  const subscriptions = getUserWatchlist(userId);

  // Subscribe to price feeds
  for (const ticker of subscriptions) {
    priceFeed.on(ticker, (price) => {
      ws.send(JSON.stringify({ type: 'price_update', ticker, price }));
    });
  }
});

High-frequency events

If you are sending more than a few events per second to the same receiver, the overhead of individual HTTP requests adds up. Each webhook delivery includes TCP handshake, TLS negotiation, HTTP headers, and connection teardown. WebSockets amortize this cost across the lifetime of the connection.

At 10+ events per second, WebSockets use roughly 1% of the bandwidth that webhooks would require.

Bidirectional communication

WebSockets let both sides send messages at any time. This is essential for features like:

• Chat: User sends a message, server broadcasts to other participants
• Collaborative editing: Client sends cursor position and edits, server merges and broadcasts
• Gaming: Client sends inputs, server sends game state updates
• Interactive dashboards: Client sends filter changes, server pushes filtered data

Webhooks are inherently unidirectional. If you need the receiver to send data back to the sender in real time, WebSockets are the only option without resorting to a second webhook channel in the opposite direction.

The hybrid approach

Most real-world systems use both. The pattern is straightforward: webhooks for server-to-server integration, WebSockets for user-facing real-time features.

┌─────────────────┐    webhook     ┌─────────────────┐   WebSocket    ┌──────────┐
│  Payment        │ ──────────────→│  Your Backend   │ ──────────────→│  Browser │
│  Provider       │   HTTP POST    │                 │   persistent   │          │
└─────────────────┘                │                 │   connection   └──────────┘
                                   │  1. Receive     │
                                   │  2. Process     │
                                   │  3. Push to     │
                                   │     connected   │
                                   │     clients     │
                                   └─────────────────┘

A payment succeeds → Stripe sends a webhook to your backend → your backend processes it → your backend pushes a notification to the user’s browser via WebSocket. The webhook handles the reliable server-to-server delivery. The WebSocket handles the real-time user notification.

// Webhook handler receives event from payment provider
app.post('/webhooks/payments', (req, res) => {
  verify_signature(req);
  const event = req.body;

  if (event.type === 'payment.completed') {
    // Update database
    markOrderPaid(event.data.order_id);

    // Push to connected browser via WebSocket
    const userId = getOrderOwner(event.data.order_id);
    wsClients.get(userId)?.send(JSON.stringify({
      type: 'order_paid',
      orderId: event.data.order_id,
    }));
  }

  res.status(200).send('OK');
});

This is cleaner than trying to make WebSockets do everything. The payment provider does not need to maintain a persistent connection to your server. Your browser does not need to poll for payment status. Each protocol does what it is best at.

Scaling considerations

Webhooks scale horizontally

Webhook receivers are standard HTTP endpoints. They sit behind a load balancer, scale horizontally, and require no shared state. Adding a server does not change the webhook URL or require any reconfiguration on the sender’s side.

The challenge with webhooks is on the sending side: managing delivery queues, retry logic, and backpressure. But as a receiver, scaling is trivial.

WebSockets require connection affinity

Each WebSocket connection is a stateful TCP session bound to a specific server process. Scaling means either:

• Sticky sessions: Route each client to the same server via load balancer affinity (IP hash, cookie-based routing)
• Shared pub/sub: Use Redis Pub/Sub, NATS, or a message broker so any server can push to any connected client
• Managed services: Offload connection management to services like Pusher, Ably, or AWS API Gateway WebSocket APIs

// Redis pub/sub for cross-server WebSocket broadcasting
const redis = new Redis();
const subscriber = new Redis();

subscriber.subscribe('notifications');
subscriber.on('message', (channel, message) => {
  const { userId, payload } = JSON.parse(message);
  const client = localClients.get(userId);
  if (client) {
    client.send(JSON.stringify(payload));
  }
});

// Any server can publish — the subscriber on the right server delivers
function notifyUser(userId, payload) {
  redis.publish('notifications', JSON.stringify({ userId, payload }));
}

At 10,000+ concurrent connections, WebSocket infrastructure becomes a non-trivial operational concern. Webhooks never have this problem because there is nothing to keep alive between events.

Reliability and delivery guarantees

Webhook reliability

Webhook senders implement retry policies. If your endpoint returns a 5xx or times out, the sender retries — typically 3-5 times with exponential backoff. This gives you at-least-once delivery: every event will be delivered at least once, but possibly more than once.

The trade-off: you must handle duplicate deliveries. Store processed event IDs and check before acting. See webhook retry best practices for implementation details.

WebSocket reliability

WebSockets provide no built-in delivery guarantees. If the connection drops — network switch, mobile user entering a tunnel, server restart during a deploy — messages sent during the disconnection are lost. The client reconnects and has no way to know what it missed.

To add reliability to WebSockets, you need:

• Client-side reconnection with exponential backoff
• Server-side message buffering or event sourcing
• Sequence numbers so the client can request missed messages after reconnecting
• A fallback mechanism (polling or webhook-to-WebSocket bridge) for messages during disconnection

This is significant engineering work. If you need guaranteed delivery between servers, webhooks provide it out of the box. If you need real-time user updates with reliability, the hybrid approach (webhook → backend → WebSocket with a polling fallback) is the standard pattern.

Server-Sent Events: the middle ground

Before we get to the decision framework, there is a third option worth considering.

If you need server-to-browser push but not bidirectional communication, Server-Sent Events (SSE) are simpler than WebSockets:

SSE uses standard HTTP streaming, works through all proxies, and the browser’s EventSource API handles reconnection automatically. For one-way notification feeds, live logs, or status updates, SSE is often the simpler choice.

Decision framework

Use this flowchart to choose:

1. Is the receiver a server or a client (browser/app)?

   • Server → Webhooks
   • Client → Continue to question 2

2. Does the client need to send data back in real time?

   • Yes (chat, collaboration, gaming) → WebSockets
   • No (notifications, live feeds) → Continue to question 3

3. How frequent are the events?

   • More than 1/second → WebSockets (or SSE for one-way)
   • Less than 1/second → SSE (simpler than WebSockets)

4. Do you need guaranteed delivery between servers?

   • Yes → Webhooks with retry logic
   • No → Either works; choose based on latency requirements

Maybe you don’t need either

Not every “real-time” feature actually needs real-time infrastructure. If your data changes every few minutes and a short delay is acceptable, simple polling or scheduled HTTP requests can be the right answer. No persistent connections to manage, no webhook endpoints to secure — just a timer and a GET request. Before you invest in WebSocket scaling or webhook retry queues, consider whether polling fits your latency requirements.

If you do land on the webhook pattern and need recurring HTTP callbacks on a schedule, Recuro handles the scheduling, retries, and monitoring so you do not have to build that infrastructure yourself.

Related resources

• Webhooks vs APIs: understanding the difference — push vs request-response patterns
• Webhooks vs polling: when to push and when to pull — push vs pull with efficiency analysis
• How to secure webhook endpoints — HMAC signatures and replay protection
• Webhook retry best practices — exponential backoff, jitter, and dead letter queues
• Webhook scheduling: send HTTP requests on a schedule — cron-based webhook delivery
• What is a webhook? — HTTP callback fundamentals
• HTTP callback — the mechanism behind webhooks
• At-least-once delivery — webhook delivery guarantees explained
• Exponential backoff — the retry strategy that prevents overload