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Online WebSocket Tester

Debug WebSocket connections in your browser. Connect to WS/WSS, send JSON or text, and watch a live send/receive log.

This client connects to the URL you enter. Messages go to that server, not to Toolbox.Hub.

Disconnected




      

  
  

    
Use cases and practical choices

          
Development, testing and operations teams can inspect chat, notification, dashboard or device-reporting channels for connection and expected messages. It does not infer business protocols or act as background monitoring or long-term message storage.

              


Connect, send, and inspect messages
  • Connect to ws:// and wss:// endpoints
  • Send text or JSON and keep a live message log
  • Optional heartbeat and subprotocols
How to debug a WebSocket
  1. Enter a WebSocket endpoint. This HTTPS site should use wss://. Supply subprotocols if required by the server; an ordinary HTTP API URL is not automatically a WebSocket endpoint.
  2. Connect and confirm an open state before sending. If it fails, check endpoint, certificate, reachability, Origin restrictions and authentication; browser error details can be limited.
  3. Enter text or JSON and send with the button or Enter; Shift+Enter inserts a line break. JSON formatting changes layout, not compliance with the server’s application protocol.
  4. Enable heartbeat only with the interval and payload the service expects. Inspect direction, time and byte count in the log, copying it if needed. Only the latest 400 entries are retained.
  5. Disconnect when done. The endpoint is remembered locally, not the entire session history; check it again before the next test environment.
WebSocket debugger FAQ
What can I test beyond chat applications?
Test standard WebSocket endpoints for notifications, device state, live dashboards or collaboration when you know their message and authentication rules. This is a generic browser client, not an automatic MQTT, Socket.IO or other application-handshake implementation. Similar terminology does not establish protocol compatibility.
Why does a command-line connection work when the browser fails?
Browsers impose mixed-content, certificate, Origin and handshake-header restrictions. They cannot freely set headers like some command-line clients. Inspect browser developer tools and server logs to distinguish rejection, authentication failure and unreachable endpoints instead of repeatedly reconnecting.
Can I set Authorization or arbitrary custom headers?
No arbitrary handshake-header controls are exposed by the native browser WebSocket API. Follow the service’s supported browser authentication mechanism rather than assuming a token placed anywhere will work. The endpoint is remembered locally, which matters if you include sensitive query parameters.
Is heartbeat a protocol ping, and are logs saved permanently?
Heartbeat sends an ordinary text message at the selected interval; it is not a customizable protocol-level ping frame. The server must understand that message. Only the latest 400 log entries remain in the current page, with no server-side archive. Copy needed logs and disconnect when finished.
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JSON formatter
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Unix timestamp
Convert between millisecond timestamps and readable dates.