WebSocket Tester
Open a WebSocket, send one message and show the first response.
Overview
The WebSocket tester opens a connection to a ws:// or wss:// endpoint, sends a single message, and displays the first response. It is the quick-check counterpart to the WebSocket Echo Tester: ideal when you just need to confirm a server is alive and replying, without the full interactive timeline.
Developers verifying a freshly-deployed endpoint, integration engineers running a smoke test, and support staff confirming a customer's WebSocket URL is reachable all need a single-shot WebSocket check. Long-tail keywords covered: quick WebSocket reachability test, verify wss endpoint with one message, and simple WebSocket smoke test online.
How it works
The tester opens a standard WebSocket connection from the browser to the supplied URL. Once the handshake completes (HTTP 101 Switching Protocols), the configured payload is sent as a text frame, and the test waits for the first incoming frame from the server. The response payload, the time-to-first-byte, and the eventual close code are surfaced; everything else (subsequent frames, ping/pong traffic) is ignored.
This single-message workflow is intentionally narrower than the Echo Tester. It is fast, deterministic, and easy to share — a teammate can reproduce the test by clicking once on the saved URL. For multi-turn conversations or binary frames, switch to the Echo Tester.
Examples
- Send
{"type":"ping"}to a custom WebSocket server, receive{"type":"pong"}, confirms the handshake and basic message routing work. - Connect to a public echo server with the string "hello", receive "hello" back, classic round-trip test.
- Subscribe to a feed by sending a JSON subscribe message and verifying the first event-frame arrives within seconds.
- A test that returns a close frame with code
1008(policy violation) instead of an echo — the server rejected the message, useful signal during integration.
FAQ
Why only one response?
The single-message model gives a clear pass/fail signal: "I sent X, I got Y back." If you need to send multiple messages or watch a long-running stream, use the WebSocket Echo Tester instead.
Does the test handle binary frames?
The simple tester sends text only. Binary support lives in the Echo Tester.
What if the server takes a long time to reply?
The test waits up to a fixed timeout (a few seconds). If no frame arrives in that window, the result is "no response" — usually meaning the server accepted the connection but is not echoing, or your subscribe message did not match what it expects.
Are connection cookies attached?
No. The tester opens a clean connection without any cookies from your browser session. For authenticated WebSockets, encode the token in the URL or in the first message after open.