WebSocket Tester

WebSocket Tester: Core Features and Principles

When developing or debugging real-time communication features, you need to quickly verify if your WebSocket service is working properly. Writing client code manually is time-consuming. This tool provides an online WebSocket client—simply enter the server address to establish a connection, send text messages in real-time, and view server responses to intuitively assess the communication process. WebSocket is a full-duplex communication protocol over TCP that allows servers to actively push data to clients. This tester uses native browser APIs to perform handshakes and send/receive frames, fully displaying the connection status and message interactions to help you troubleshoot issues like protocol handshake failures or message format errors.

Why Choose Our WebSocket Tester?

• No installation required. It works right in your browser without any plugins, lowering the barrier to testing.
• Supports both the unencrypted ws:// and encrypted wss:// protocols, making it suitable for both development and production environments.
• Comprehensive message logs and status prompts clearly display the exact times for connection openings, closures, and errors, along with timestamps for every message, making it easy to pinpoint issues.

How to Use the Tool

1. Enter the complete WebSocket server address in the address bar, such as wss://echo.websocket.org or ws://localhost:8080/chat. Note that the protocol prefix cannot be omitted.
2. Click the "Connect" button. The tool will immediately initiate a WebSocket handshake. Upon a successful connection, the status will change to "Connected" and display the connection establishment time.
3. Type the text you want to send in the message input box below and click the "Send" button. The message will be sent to the server through the established connection.
4. Server replies will be displayed in real-time in the message log area. Each message includes a precise timestamp and a direction indicator (Sent/Received) to help analyze the response sequence.
5. After testing, click the "Disconnect" button to close the connection. The status will update, and message transmission will stop.

Input Example: Address wss://echo.websocket.org, send message "Hello WebSocket".

Output Example: Message log displays → 16:22:01 Connected / 16:22:05 Sent: Hello WebSocket / 16:22:05 Received: Hello WebSocket / 16:22:10 Disconnected.

Frequently Asked Questions (FAQ)

• Why does it say "Connection Failed" or "Connection Refused"?
  First, check if the server address and port are correct, and ensure the service is running and allows external access. Second, the browser's same-origin policy or network firewalls might block ws connections. If you are using a wss service with a self-signed certificate, you must first trust the certificate in your browser.
• Can the tool send binary messages or use custom subprotocols?
  No, the current version only supports sending text messages. If you need to test binary data, you can convert it to a Base64 string before sending, provided the server can decode it. Custom subprotocols are also not supported.

Important Notes

This tool only recognizes ws:// and wss:// protocol addresses. A successful connection only indicates that the TCP link and WebSocket handshake are complete; it does not guarantee that your business logic is correct. When testing over a public network, messages sent via plaintext ws may be intercepted by a man-in-the-middle, so it is recommended to use wss for sensitive data. If there is no response for a long time, check your network connectivity, server load, or the browser console for error details. Please disconnect promptly after testing to avoid tying up server resources.

Technical Notes & Usage Tips

During the WebSocket handshake phase, headers such as Sec-WebSocket-Key and Sec-WebSocket-Protocol are included. A 101 status code returned by the server indicates a successful protocol switch. If errors like 400 or 404 are returned, it is usually due to an incorrect path or server configuration. While debugging, you can also open the Network panel in your browser's developer tools and check the Frames tab to observe frame payloads and directions. For frequent connection testing, we recommend setting up a local intranet echo service, such as ws://localhost:9090, to reduce reliance on public testing services. A typical input like wss://echo.websocket.org is a public echo service that returns any sent text exactly as is, making it ideal for verifying basic connectivity.