WebSocket Echo Servers for Testing
Test your websocket clients against public echo servers
What is an echo server?
An echo server accepts a connection and reflects every message you send straight back to you. It is the simplest possible way to verify that your client code can open a connection, send a frame, and receive a response, without writing a backend of your own.
Three servers, one host
Three public echo servers are now available under echo.rapidtoolset.com:
| Protocol | URL |
|---|---|
| WebSocket | wss://echo.rapidtoolset.com/ws |
| Socket.IO | https://echo.rapidtoolset.com/socketio |
| SockJS | https://echo.rapidtoolset.com/sockjs |
Each server speaks its own protocol natively. The WebSocket endpoint accepts raw wss:// connections. The Socket.IO endpoint runs a full Socket.IO server so handshakes, namespaces, and acknowledgements all work as expected. The SockJS endpoint provides the standard SockJS fallback negotiation for environments where native WebSockets are unavailable.
Tools that use these servers
The browser-based test clients on the site connect to these servers out of the box:
- WebSocket Test Client opens a raw WebSocket connection, sends messages, and displays frames in real time.
- Socket.IO Test Client connects via the Socket.IO protocol, lets you emit named events, and shows incoming events in a live log.
- SockJS Test Client connects through the SockJS client library and tests the full fallback negotiation path.
Free to use, with limits
The echo servers are free and require no authentication. They are rate-limited to prevent abuse, so they are intended for manual, interactive testing only. Automated scripts, load tests, and bots will hit the rate limit and be rejected.