WebSocket Tester
Connect to any ws:// or wss:// endpoint, send messages, and inspect live events with timestamps. 100% client-side.
New to this tool? Click here for instructions
WebSocket Event Reference
| Event | Description |
|---|---|
| OPEN | Connection established. Ready to send and receive messages. |
| Message received from the server. JSON is auto-detected and pretty-printed. | |
| SEND | Message sent to the server from this client. |
| ERROR | A connection error occurred. Often followed by a CLOSE event. |
| CLOSE | Connection closed. Shows close code and reason if provided by the server. |
Close Codes
| Code | Meaning |
|---|---|
| 1000 | Normal Closure - clean, intentional close |
| 1001 | Going Away - server shutting down or page navigation |
| 1002 | Protocol Error - invalid framing |
| 1003 | Unsupported Data - binary data when text expected |
| 1006 | Abnormal Closure - connection lost without close handshake |
| 1007 | Invalid Frame Payload Data - not valid UTF-8 |
| 1008 | Policy Violation - server rejected the message |
| 1009 | Message Too Big - payload exceeds server limit |
| 1011 | Internal Error - server encountered unexpected condition |
| 1015 | TLS Handshake - TLS failure (not sent over the wire) |
Public Test Endpoints
wss://echo.websocket.org- echoes back everything you sendwss://ws.postman-echo.com/raw- Postman echo serverwss://socketsbay.com/wss/v2/1/demo/- public demo channel
How to Use the WebSocket Tester
To use the WebSocket Tester, follow these steps:
1. Enter a URL: Type or paste a ws:// or wss:// URL in the field at the top.
2. Connect: Click the 'Connect' button. The indicator will turn green when the connection is established.
3. Watch the log: Open, receive, send, error, and close events will appear in the event log with timestamps.
4. Send messages: Type any text or JSON in the send box and click 'Send'. JSON will be auto-detected and pretty-printed in the log.
5. Disconnect: When done, the connection will be closed cleanly, and the log will show the close code.
When to Use the Tool in Real Workflows
Use the WebSocket Tester when you need to test WebSocket connections for real-time applications, such as chat, stock price feeds, or any other application that requires frequent updates.
It's particularly useful for developers who need to debug connection issues, test gRPC-Web and GraphQL subscriptions, or ensure that their WebSocket servers are functioning correctly.
How It Works
The WebSocket Tester establishes a direct WebSocket connection from your browser to any URL you enter. It logs all lifecycle events, including onopen, onmessage, onerror, and onclose, with precise timestamps.
Messages are inspected, and if the server sends valid JSON, the tool automatically pretty-prints it for easy reading.
Your connection history is saved to localStorage, so frequently used endpoints are just a click away.