WebSocket Tester
Free online WebSocket tester. Connect to any ws:// or wss:// endpoint, send messages, inspect frames with timestamps and sizes, auto-send on an interval and save message templates. 100% local.
What is a WebSocket tester used for?
It connects directly to any WebSocket endpoint from your browser so you can send messages, watch what the server returns and debug the handshake, framing and payloads of realtime APIs, chat servers or IoT devices.
What is the difference between ws:// and wss://?
ws:// is unencrypted WebSocket, wss:// is WebSocket over TLS. If this page is loaded over HTTPS, browsers block insecure ws:// connections as mixed content, so use wss:// endpoints here.
Are my WebSocket messages sent through your servers?
No. The connection is opened directly from your browser to the target host. The tool only renders the log — no proxy, no storage, no upload.
Can I test binary WebSocket frames?
Yes. Incoming binary frames are shown as a hexadecimal preview with their byte length, alongside text frames with character counts.
How does the auto-send feature work?
Enable the auto-send checkbox and set an interval in seconds. The current message is then sent repeatedly at that rate while the connection stays open — handy for heartbeat and ping tests.
What are message templates?
Type a frequent message, press Save as template and it is stored in your browser (localStorage). Templates are listed in the dropdown so you can reload them with one click. They never leave your device.
Can I pass subprotocols in the handshake?
Yes. Enter a comma-separated list in the protocols field and they are passed to the WebSocket constructor as the second argument, exactly like a native client would.
Why did my connection close with a specific code?
The log shows the WebSocket close code (for example 1006 for abnormal closure, 4400+ for app-defined errors). Check the server logs together with the code to diagnose the cause.
How to Use WebSocket Tester
WebSocket Tester opens raw ws:// and wss:// connections straight from your browser. Frames flow directly between your device and the target host — there is no proxy, nothing is logged or uploaded, and message templates stay in your browser's local storage.
- Type the endpoint URL (wss://host/path) into the URL field. If the page is served over HTTPS, insecure ws:// URLs trigger a mixed-content warning and are blocked — switch to wss://.
- Optionally list subprotocols (comma separated) and press Connect. The status badge moves from Connecting to Connected and the handshake appears in the log.
- Type a message and press Send, or press Enter. Each frame is logged with a direction arrow, timestamp and byte size; incoming binary frames appear as a hex preview.
- Turn on the auto-send checkbox with an interval in seconds to repeat the current message — useful for heartbeat and ping tests.
- Save frequent payloads with Save as template, reload them from the dropdown, and use Clear log to reset the console.
Watch the close code in the log when a connection drops: 1006 means an abnormal network-level close, while 4400+ codes usually come from the application — pair it with server logs to find the cause.
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