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Hooklistener
⚡Real-Time WebSocket Debugging

Free WebSocket
Debugger & Tester

Inspect WebSocket messages in real-time. Simulate network conditions like latency, jitter, and packet loss.
Perfect for debugging chat apps, live dashboards, multiplayer games, and any real-time application.
Also check out our webhook debugger for HTTP webhook testing.

1

Create Endpoint

Get a unique WS URL

2

Connect Client

Point your app to it

3

Debug & Test

Inspect & simulate

Start Debugging WebSocketsSee How It Works
Real-Time Inspection
Network Simulation
Multiple Sessions
Powerful capabilities

Everything You Need to Debug WebSockets

A complete WebSocket debugging toolkit. Inspect messages, simulate network conditions, and test real-time applications with ease.

Real-Time Message Inspection

View all incoming and outgoing WebSocket frames instantly as they flow. No refresh needed.

Latency Simulation

Add artificial latency (0-30 seconds) to test how your app handles slow connections.

Jitter & Packet Loss

Simulate unreliable networks with configurable jitter and packet loss percentage.

Multiple Sessions

Track up to 50 concurrent WebSocket connections per endpoint. Debug multiple clients at once.

Send Messages to Clients

Push messages directly to connected clients from the debug console to test responses.

Auto-Response

Configure automatic responses to test client behavior under echoing conditions.

Session Lifecycle Tracking

Track connection time, remote IP, user agent, and disconnect reasons for each session.

Secure HTTPS Endpoints

All debug endpoints use WSS (WebSocket Secure) with unique, unguessable URLs.

Endpoint Management

Create, pause, and delete endpoints. Per-organization isolation with plan-based limits.
Simple setup

How to Debug WebSockets in 4 Steps

From setup to debugging in under a minute. No complex configuration, just instant WebSocket inspection.

01

Create a Debug Endpoint

Create a new WebSocket debugging endpoint from your dashboard. You'll get a unique WSS URL.

wss://ws.hooklistener.com/my-debug-endpoint-abc123
02

Connect Your WebSocket Client

Point your application's WebSocket client to the debug endpoint URL instead of your server.

const ws = new WebSocket(
  "wss://ws.hooklistener.com/my-debug-endpoint-abc123"
);

ws.onmessage = (event) => {
  console.log("Received:", event.data);
};

ws.send(JSON.stringify({ action: "ping" }));
03

Inspect Messages in Real-Time

Watch all messages flow through the debug console. See direction, timestamps, and payload content.

← Incoming  │ 10:30:15.234 │ {"action": "ping"}
→ Outgoing  │ 10:30:15.456 │ {"action": "pong", "ts": 1705746615}
← Incoming  │ 10:30:16.001 │ {"type": "subscribe", "channel": "updates"}
→ Outgoing  │ 10:30:16.089 │ {"type": "subscribed", "channel": "updates"}
04

Simulate Network Conditions

Add latency, jitter, and packet loss to test how your application handles poor network quality.

Network Simulation Settings:
├── Latency:     250ms (base delay)
├── Jitter:      ±50ms (random variation)
└── Packet Loss: 5% (drop probability)

Message sent with 287ms delay (250 + 37ms jitter)
Message dropped (5% packet loss triggered)

Ready to debug your WebSocket connections?

Create Your First Debug Endpoint
webhook.site alternative

Graduating from webhook.site (RequestBin)? Hooklistener takes you further.

Move from one-off bins to a production-grade webhook platform with replay, forwarding, and monitoring built in. Compare features side-by-side and migrate in minutes.

Keep every payload

Persist webhook history for 14+ days, search instantly, and replay to any environment.

Forward & transform

Send events to QA, staging, and production with conditional routing and transformations.

Built for teams

Invite collaborators, mask secrets, and stay audit-ready—no public bins or shared tokens.

Start free with HooklistenerView full comparison

Comparison FAQs

How is this different from browser DevTools WebSocket inspection?

Browser DevTools only show WebSocket frames for that browser session. Hooklistener captures messages server-side, supports network simulation, and lets you debug multiple clients simultaneously from a single dashboard.

Can I test WebSocket reconnection logic?

Yes. Use packet loss simulation to trigger disconnections and verify your client's reconnection behavior. You can also pause endpoints to force clients to handle connection failures.

Does this work with Socket.IO?

Socket.IO support is coming soon. Currently, we support standard WebSocket connections. Stay tuned for Socket.IO and MQTT protocol support.

Frequently Asked Questions

Everything you need to know about debugging WebSocket connections

What is a WebSocket debugger and why do I need one?
A WebSocket debugger is a tool that intercepts and displays WebSocket traffic in real-time. Unlike HTTP requests that are one-shot, WebSocket connections are persistent and bidirectional, making them harder to debug with traditional tools. A WebSocket debugger lets you see every message flowing in both directions, helping you identify issues with message ordering, payload structure, and connection handling.
How is this different from browser DevTools?
Browser DevTools only show WebSocket traffic for that specific browser tab. Our debugger captures traffic server-side, meaning you can debug multiple clients simultaneously, see connections from native apps or IoT devices, and share debugging sessions with your team. Plus, DevTools don't let you simulate network conditions or send test messages to clients.
Can I simulate network latency and packet loss?
Yes! Our WebSocket debugger includes a full network simulation suite. You can add base latency (0-30 seconds), jitter (random variation in latency), and packet loss (0-100%). This is perfect for testing how your application handles slow or unreliable connections without deploying to a real-world environment.
What is jitter and why should I test for it?
Jitter is the variation in latency over time. Real networks don't have consistent delays - sometimes packets arrive quickly, sometimes slowly. Testing with jitter helps you identify issues like message ordering problems, race conditions, and UI flickering that only appear under realistic network conditions.
How many concurrent WebSocket connections can I debug?
Each debugging endpoint supports up to 50 concurrent WebSocket connections. You can create multiple endpoints to debug different parts of your application independently. The free tier includes 3 endpoints per organization, with higher limits on paid plans.
Can I send messages to connected WebSocket clients?
Absolutely. From the debug console, you can select any connected client and send custom messages to test how your client handles different payloads. You can also configure auto-response to automatically echo messages back, which is useful for testing client-side message handling.
How long are WebSocket sessions and messages stored?
WebSocket debugging data is stored in-memory for real-time inspection. Sessions and messages are retained for 30 minutes of inactivity, after which they're automatically cleared. This is intentional for debugging tools - we focus on real-time inspection rather than long-term storage.
Is my WebSocket traffic secure?
Yes. All debug endpoints use WSS (WebSocket Secure) with TLS encryption. Each endpoint has a unique, unguessable URL, and your traffic is isolated from other users. We never share or index your debugging data.
Does this work with Socket.IO or MQTT?
Currently, we support standard WebSocket connections. Socket.IO and MQTT protocol support are coming soon! Socket.IO uses WebSocket under the hood, so basic inspection works, but full Socket.IO-specific features like namespace handling are on our roadmap.
Can I use this to debug production WebSocket issues?
While primarily designed for development and testing, you can use our debugger to inspect production traffic by routing connections through a debug endpoint. However, be mindful of the latency this adds. For production debugging, we recommend using our observability features instead, which provide insights without intercepting traffic.

Have more questions about WebSocket debugging?

Check out our developer guides

Ready to Debug Your WebSocket Apps?

Stop guessing why your WebSocket connections fail. Get real-time visibility into every message, simulate network conditions, and ship with confidence.

Start Debugging WebSocketsOr Try Our Webhook Debugger

Free tier available • No credit card required • Setup in seconds