Online WebSocket Tester

Online WebSocket Debugger

The Online WebSocket Debugger is a free, browser-based tool designed for frontend developers, backend engineers, and QA testers. Without installing any software, you can connect to any WebSocket server directly from your browser, send and receive messages in real time, and streamline the entire WebSocket development and testing workflow.

Key Features

• ws/wss Protocol Support: Works with both plain ws:// and encrypted wss:// connections, covering local development and production environments.
• Real-Time Messaging: Send text or JSON messages instantly after connecting, and see server-pushed messages appear in the log immediately.
• Color-Coded Message Log: Sent messages (green), received messages (blue), and system events (gray) are clearly distinguished for quick scanning.
• JSON Formatter & Minifier: Built-in buttons to format or minify JSON payloads, with automatic validation to catch syntax errors before sending.
• Address History: Automatically remembers up to 10 recently used URLs for quick reconnection without retyping.
• Connection Status Indicator: Live status light shows connecting, connected, disconnected, or error states, plus an elapsed connection timer.
• Message Counter: Real-time sent/received message counts displayed at the bottom, useful for load testing and interface verification.
• Auto-Scroll Toggle: Pause auto-scrolling to review earlier messages during high-frequency data streams.
• Keyboard Shortcut: Press Ctrl+Enter to send messages quickly without reaching for the mouse.

Use Cases

• Frontend developers verifying WebSocket API data formats and interaction logic.
• Backend engineers testing push notification services, chat systems, or real-time data streams.
• QA testers running functional and regression tests against WebSocket endpoints.
• Developers learning the WebSocket protocol who want a quick hands-on experience with full-duplex communication.

How to Use

1. Enter a WebSocket server address (e.g. wss://echo.websocket.org) in the connection bar and click Connect.
2. Once connected, type your message in the send area and click Send or press Ctrl+Enter.
3. The message log will display all sent and received messages in real time, along with system events like connection and disconnection.
4. Use the Format JSON or Minify JSON buttons to construct well-formed JSON payloads.
5. Click Disconnect when done, or simply close the browser tab.

What Is WebSocket?

WebSocket is a full-duplex communication protocol over a single TCP connection, introduced as part of the HTML5 specification. Unlike the traditional HTTP request-response model, WebSocket allows the server to push data to the client at any time, making it ideal for chat applications, live market data, online gaming, collaborative editing, and any scenario requiring low-latency bidirectional communication.

FAQ

Q: Which WebSocket protocol version is supported?
A: The tool uses the browser's native WebSocket API, which supports the RFC 6455 standard and is compatible with all mainstream WebSocket server implementations.

Q: Can I connect to a local server?
A: Yes. Enter ws://localhost:PORT to connect to a local WebSocket service. Note that some browsers block plain ws:// connections from https pages; in that case, use a wss:// endpoint instead.

Q: Are message logs saved?
A: Logs exist only in the current browser session. Refreshing or closing the page clears them, and nothing is uploaded to any server, keeping your debug data private.

Q: Where is the address history stored?
A: History is saved in your browser's localStorage and is only accessible on your own device. It is cleared when you clear your browser data.