WebSocket Tester
Open a WebSocket connection to any ws:// or wss:// endpoint, send text or JSON payloads, and inspect incoming messages with timestamped logs. Free online realtime API testing tool.
Connect to any WebSocket endpoint, send messages, and inspect live responses directly in your browser. Great for API debugging, event stream testing, and real-time integration checks.
Live event log (0/250)
Features
Instant WebSocket Connect
Open and close WebSocket sessions in one click with clear live connection state.
Real-Time Message Flow
Send text or JSON payloads and inspect incoming messages with timestamped logs.
Protocol and Payload Controls
Test optional subprotocols and validate JSON payloads before sending.
Copy Full Session Logs
Copy complete event history for bug reports, QA notes, and team debugging.
Use Cases
Realtime API Debugging
Verify payload contracts and server responses for chat, live feed, or collaboration APIs.
QA Environment Validation
Smoke test staging socket endpoints without writing custom frontend scripts.
Incident Triage
Capture quick reproduction logs when message delivery or connection drops fail in production.
Protocol Experiments
Try alternate payload formats and subprotocol values during backend integration.
Authentication Flow Testing
Validate token-based handshake flows by sending auth payloads immediately after connection and observing server acknowledgment or rejection responses.
Load and Reconnection Behavior
Manually trigger disconnects and reconnects to verify that your server handles session resumption and message replay correctly under unstable network conditions.
About WebSocket Tester
How this tool works
The tool uses the browser WebSocket API to create a direct client connection, send messages, and stream responses into a structured event log. No server-side proxy is required for basic testing.
When to use this
Use it while developing realtime features, validating socket auth behavior, testing payload schema changes, or collecting reproducible logs during QA and support investigations.
Supported connection types
The tool supports both ws:// and wss:// endpoints, custom subprotocols, and arbitrary headers where the browser permits. This covers most standard WebSocket servers including Socket.IO, STOMP, and raw protocol implementations.
Reading the event log
Each entry in the event log is timestamped and labeled as sent, received, open, close, or error. This structured view makes it straightforward to trace message ordering, measure round-trip timing, and identify unexpected disconnects during testing.
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Frequently Asked Questions
Can I test both ws:// and wss:// URLs?
Yes. The tester supports both unsecured ws:// and secure wss:// endpoints. When you provide http/https URLs, the tool converts them automatically to ws/wss.
Does this tool support JSON payload validation?
Yes. Switch Message Type to JSON and the tool validates your payload before sending so malformed JSON is caught immediately.
Why does my connection fail in the browser?
Common reasons include invalid URL, server offline state, authentication requirements, TLS certificate issues, or endpoint restrictions that reject browser-origin connections.
Can I test WebSocket subprotocols?
Yes. Add a comma-separated subprotocol list in the Subprotocols field and reconnect. The browser will include them in the handshake.
Can I export logs from the session?
Yes. Use Copy Logs to copy all events with timestamps and message direction, then paste into bug trackers or team chat.
Can I test WebSocket connections that require authentication headers?
The WebSocket API in browsers does not support custom headers during the handshake. For auth-protected endpoints, use token-based query parameters or subprotocol-based auth patterns instead.
Is this WebSocket tester free to use?
Yes. It is 100% free with no account required. All connection handling runs directly in your browser and no message data is stored or sent to any server.